If you want to put your money on a new 3D shooter, why should you buy something that looks like a five year old game when you can get something with the looks of UT2003?
You can? I thought the little matter of licencing pretty much ruled that out. When are you paying the licence fee for a MOS/OS4 port of UT2003? ;-)
Of course you can always play UT2003 on a PC...but where's the fun in that? :-)