Unix is more ready for the desktop than Amiga is for the enterprise market.
I believe Hyperion has made it quite clear that OS4 is going to be a single-user system. How can any OS be taken seriously as an enterprise system unless it offers multiple accounts and a server/client login system?
I agree, though, that the world is going Linux crazy. Enterprise servers and such are purpose-built machines made from carefully selected hardware and meticulously organized software. Being a server is about more than just serving web pages. Try running Perl or PHP on an Amiga and see how secure it is with no user accounts.
Desktop machines are a mish-mash of various parts which may not like to share resources with each other. Linux doesn't offer the flexibility that desktop users need. Install a single rouge program on a Linux machine, and it's likely to spam, spy, and infect your system just like any Windows machine. Amiga will be fine for a desktop machine, but for anything else, it's a joke.
Enterprise systems are already robust and powerful. Desktop systems are crap. Future desktop systems will probably be made from reengineered and redesigned Linux components, but Linux by itself is a joke in the desktop market.
If Amiga had been based on a "real" OS like Linux or QNX, it might have a chance at the enterprise market, and even the desktop market. With no account system, though, OS4 is of little use but as a terminal or game machine. Useful, but hardly worth talking about.