Okay just what exactly is bloat? and programs running in the background? Do you mean processes? If you are complaining about that kinda thing or "services" that run in the background, you obviously never used Linux or any Unix variants..
Sure processes and services do run in the background on *nix style systems they are called daemons there.. It's a normal part of modern operating systems and it dates back to mainframe days. The footprint of the modern OS has grown (even BeOS has this stuff going on)..
I don't think I'd want to use XP if it just was what could boot off a floppy.. It has a different approach and different design goals.
If you don't like windows you don't have to run it, same goes from BeOS, Linux, etc.. There are alternatives. The Amiga is a nice one, but if you add a webserver, virtual memory, messenger service, ftp, etc. to the AmigaOS it would get pretty big too..