Awe..now I feel bad! I'm sorry I used that as an example but let me explain without too much TMI: If a large bathroom is empty and I need to do #2 I will purposely go to the back corner (if clean with paper) to do my business. But it always seems someone comes and sits right next to me when there are like 15 to 20 empty stalls.

Maybe it's just me, but if I go into a large bathroom with 15 empty stalls, and I see feet in the far corner, I know what they are doing and I avoid.

Hope this explains.
ETA: And I don't think this makes someone self centered and rude. Just like I don't think saving seats is self centered and rude. I just think some people don't think about things like that as bothering someone and it just happens.