Your forgetting something
No one is required to use the mouse that comes with the Mac... if you don't like it simply plug in just about any old usb mouse that you do like. My Logitech Roller ball wireless works just great with the G5 and so does my Mickey Soft wireless split keyboard. Remember, it doesn't have to come from Apple to work.
Here's a list of non-apple hardware I use with the G5:
Logitech Roller ball wireless mouse
Microsoft wireless keyboard
Creative 7.1 sound system
Belkin 7 port usb hub
Corsair Pc3200 400 xml ram
Linksys 4 port router
Com Plus cable modem
Epson usb flat bed scanner
Hp 4550 color laser
Hp 2420 Black & white laser
Maxtor 200 gig external hard drive
Samsyng 20" SyncMaster 213T flat monitor
View Sonic 19" flat monitor
Sony usb external dvd burner
Only thing I have found that the G5 won't use is my Ibm 4019 b&w laser printer, and that is only cause it is about 15 years old and I can't find an OS x driver for it. Let me know if you know where one is...
And yes, Apple is competting for the same market, and doing a rather good job at it too, by building a better mouse trap so to speak. Almost all new Apple users come from the dos/winders world trying to escape the hassle of running winders...