At least in Japan, one of the pronunciations of "4" means "death," so the number is often avoided in places like hospitals, much like Western buildings may lack a 13th floor.
I don't mind the 4400, really; it's a decent performer, has an ATI video controller with upgradeable VRAM, and can use industry-standard 5.25" drives without worrying about bezels and the like. I even found a power supply out of a PC that's compatible with the one used in the 4400, so that was a first (the G3s and earliest G4s are the only other Macs I've seen that can use standard power supplies).
The RAM thing is kind of weak, though, especially the picky nature of it. About the only other Macs that use that type of RAM are clones, though some PCs will use it, as well, so with some hunting it's not too hard to source from recyclers and the like.