It's not 3D that ruined their creativity, it's all the buyouts and takeovers. They can't make challenging games because occasional gamers will not buy the game. They make them mouse driven so people without a joystick can play.
Take an RTS if you play online both sides build up a small army and rush each other. The game lasts less then 2 minutes. There is no variation to this type of play. The only stand out to this Starcraft, it was designed a lot better and you can get long games happening.
More and more effort is put into 'looks'. I'm sure it impresses the execs who control the budget. You simply won't get the same quality of games nowadays unless it is done by a small developer.
It's all to do with the price of development, each new generation of console requires between one third and one half extra staff, and also extra development time, yet the cost of a game at retail, and the profit made, have not gone up anywhere near as much.
So it takes a massive investment to create a AAA product, which only the biggest can manage. Hence all the mergers and lack of risk taking. Lots of games make no money at all.
To my mind, the really creative stuff is happening on the console indie market, and PC flash and java games. They can afford to take a few more risks there.
As for the demise of the Amiga market...before I got into game dev, I worked in games retail, and many Amiga owners came in asking if Wolfenstein, wing commander, Ultima Underworld, and eye of the beholder 3 were coming out on the Amiga.
Another problem was PC versions being better: such as Frontier Elite 2 being texture mapped, A lot of adventure games being talkies, and having more colours, with less disk swapping etc.
Also, being squeezed by the console at the low end.
Looking back, I think the A500+ wasn't enough of a step up, and nor was (my baby!) the A1200.
