I can see where you're coming from here. Not to hate on all tactical/milsim players but I think they do it to indulge in their egos. [Am I saying that right?] I was playing with a guy the other day who had like 3 different setups for his A5, stocks,shrouds, the whole package. He felt it was necessary to announce to the entire room that he was changing his barrel bore. Like karnokr said, some milsim players think it's more important to create an 'image' for themselves than actually playing.
From another perspective, a lot of people who play paintball join because of the milsim appeal to it. If we didn't have milsim players there definitly wouldn't be many people wanting to try out paintball.