Why was there nothing after os 3.9?

[Sean Cunningham]

But they could have kept going with the 68060 for a while if they managed to contain costs to Apple Quadra levels levels.  That would have bought them time to port the OS to PPC.  The PPC CHRP hardware was already there for them to use-they could have fitted the machines with 604's and high end graphics cards- Amigans always would pay to be ahead of the curve-Amiga at launch was not cheap!  Later economies of scale lets you compete on price too

I'm thinking you're misremembering the price of Quadras.  The Quadra 700, the most directly equivalent product to the Amiga 4000, though released the year prior, was $6000 base price, over $2000 more than the Amiga.  The Quadra 950, released the same year as the A4000 was $7200.  

The Amiga was always cheaper than a roughly equivalent Mac.  Amigans, some, spent a lot of money on peripherals but not on their base systems, relative to what competing Mac and name-brand Intel boxes cost.  But still, Amigans were not really spenders.  And they were rampant pirates.  This, and Commodore's disinterest in its dealer base, made it practically impossible for the small, independent Amiga dealer to exist anymore by the early 1990s.

AGA was done in a year by a couple of engineers who decided that AAA was going nowhere and that something else needed to be done.

It was just too little, too late.  Once games looked better and played better on DOS machines it was all over.  It didn't really matter that for some specific animation and motion graphics based work the AGA offered slight performance and capabilities not to be found on any Mac or PC.  I didn't give a crap about DOOM but I do remember being particularly depressed when I first saw how much better Syndicate was on a garden variety VGA system.

[Sean Cunningham]

CBM failed to get a foot into the business market (as IBM did) or into the creative market (as Apple did)...

That bolded part isn't true.  The Amiga owned the desktop video market, at the hobbyist level as well as professional level thanks in no small part to NewTek.  However difficult it was to sell an Amiga to your average computer user for...whatever...VideoToasters sold as fast as NewTek could produce them.  You only need one "killer app" or suite to dominate a particular niche market and the Amiga had it.  NewTek was the tide that lifted all boats where animation and video were concerned.

Commodore going belly up created a significant problem for NewTek in this regard because the demand for the VideoToaster was only going up when all of a sudden you couldn't get any more host Amigas.  The demand was so high that VideoToaster resellers were buying dead Amiga 4000s for up to $1500 in Los Angeles in 1994 and 1995 so that they could cobble together working systems (the same as we were doing at Digital Domain to keep as many of our Personal Animation Recorder stations up as possible...what a crap model the A4000 turned out to be).  It was 1999 before the NT version of the Toaster was released.  Uncoupling Lightwave from the Toaster in 1994 is likely just about all that kept revenue flowing though I'm betting the days of Ferraris and private jets was behind them.

At the time two major primetime series had visual effects done by Amigas (Babylon 5 and SeaQuest DSV).  It would be a few years later, after the Amiga was out of the picture, before the Mac made real inroads in these areas once dominated by the Amiga.  Commodore themselves more or less behaved as if they were unaware of this phenomenon but had they fully embraced just this one facet (while improving gaming performance) and not tripped over their own mis-managed feet they'd have been okay.  

In 1994, when they went under, there was nothing even close to the VT on any other platform and, in fact, neither Apple, SGI or the Windows market had the depth of both software and hardware solutions for this market performing at the standards and quality of what was available on the Amiga.  SGI tried coming out with video capable boards and they were a complete joke.  The best way to get high quality video in and out of an SGI in 1994 was for it to be networked to an Amiga with the hardware and software available on that platform (without spending a $250K for a Flame or better).  Commodore could not have picked a more ironic time to go out of business because it was when they were the absolute strongest in a very new, very lucrative market.

[Sean Cunningham]

No.  It wasn't luck their not paying attention to and then embracing, both barrels, all eggs in the basket that NewTek delivered, strip-o-gram style, right to their doorstep.  That's mis-management and bad decision making.  That's continued lack of intelligence across two generations of VideoToaster.  

They went out of business during the Toaster4000 era and NewTek's expansion into NLE and experiments with supercomputer acceleration for Lightwave when it was still exclusively bundled with the Toaster.  The A3000 was already a long discontinued product and not an issue, ultimately.  You're talking about a phenomenon years before they went out of business, during the initial VT craze.  Plus, enterprising folks got VTs working in A3000s.  We had one in the Media Lab at CalArts I'm pretty sure, though I may be confusing that with one of the TA's personal systems.  Nothing A2x00-based was viable passed 1993, no matter what you put into it and '030s definitely need not apply, unless you're talking really low end, switcher-only type work.

During this time you had two different interesting phenomenons happening as well, both of which Commodore benefitted from that had no connection to anything (or nothing) they were doing to try and sell Amigas.  First, for the original VT, if you were actually using it as a switcher and video effects box the Amiga was essentially just a power supply for the thing folks really wanted to be using.  So you had a lot of people who wouldn't have otherwise bought an Amiga, or computer at all, doing so just so they could run the VideoToaster and do what it did.  Then you also had people buying VideoToasters, and Amigas, with no interest in the video switching capabilities of the Toaster whatsoever and had it functioning, basically, as a dongle for running Lightwave which, for a period, had no peer on the microcomputer level.

To still not get it, two years after the A3000 is discontinued, they simply failed to understand what was actually being done with their own product which meant they couldn't capitalize or expand on that.  That's got SFA to do with "luck".  That's what you call "stupid".

[Sean Cunningham]

Once my Amiga 4000 died I went sans computer for a year, maybe more.  I eventually bought a Neko Tech Mach 1 (DEC Alpha 21064A, I believe) that I did little more than surf the web on for a while and run DOS-V cover discs (via FX!32) from Japanese magazines I'd get in Little Tokyo.  

The Intel emulator became good enough and fast enough that I was able to do Premiere Pro editing with an installed Perception Video Recorder but it wasn't a fun computer.  NT 3.51 was really, really boring.  I ended up buying a used NeXTStation Turbo Color and that was a lot more interesting.  By this point I was doing all my gaming on the Sega Saturn.  It wouldn't be until several years later that a buddy of mine got me hooked on Quake3 Arena, Rocket Arena, Counter-Strike and Urban Terror that I returned to playing games exclusively on the desktop.