Games are like they are today because PEOPLE BUY THEM THAT WAY. The game market is growing noth shrinking. Just because you dont like the way its going doesnt mean everybody else does.
If doom 3 came out and nobody purchased it I am sure ID would try something different, but when they know they can make a few more million doing the same old shit they WILL.
I am sure M$ could upgrade thier floppy drivers if people actually still used thier floppy for anything these days. BTW I just loaded my email, launched 2 new sites in IE and browsed the HD on my server all while win2k is formatting my 3.5" 1.44 floppy in the background (light on the drive never went out). Does your amiga have a cartridge port? My c64 does... dont compare new machines with functions on older ones that are OBSOLETE.
Pre made code is nice because its usually somewhat optimized and checked for bugs before its sold. Do you want to rewrite common networking routines every time you make a program that uses the LAN? No you want to grab the common building blocks and then make your specific function work.
As far as a demo scene goes, I play games not demo's. The DEMO's show that if you have nothing else going on on the machine you can get some nice looking graphics function up and running. Too bad you cant do that in a game because it takes 100% of the machine for that function. What impresses me on the PC is 3d sound (by Areal RIP) that actually made you think something was behind you in a game. Large compressed textures like in Unreal Tournament 2003 that make things look alot nicer. Environmental bump mapping so objects look like they have a texture to them in 3d. Being able to run in high resolution 3d at 60+ fps on a system with a $69 video card at a refesh that doesnt hurt my eyes. Being able to play a 4v4 game of Age of kings against real people with 1600 units running around in real time over the internet while I am in my room on a rainy day. The fact that all of the cool functions developed in hardware end up as a usable function in Direct X so they end up being used in the games that come out after.
RTS ,FPS, and flight simulator type games (some good some bad) have no equal outside of the intel PC period.
Having said that racing games, shootemups, and arcade type games are 100% better on cheap dedicated hardware that runs on a big screen TV (well next to the original arcade machine anyway).
People need to have an open mind and use the best platform for what they want to do, this usually means using more then 1 companies product or having dedicated machines for specific tasks. Anybody that sits there spouting off the amiga is the best game machine in the world is stuck in a time vacuum while the rest of the world is moving on. Each machine that I own had its time in the limelight for gaming, and I enjoy playing those classic games on that hardware from time to time. But the most powerfull architexture is always the one that just came out and it will always be able to do something that the older machine just cant do because it is faster, has more memory or just because new technology came out allowing it to do so.
If commodore was still around they would probably be making machines that are alot closer to the PC then to the old amiga's because thats where the technology and the user base was going. If you cant continuously inovate you end up with no market share (apple), or extinct (3dfx).