Has anyone bothered to consider that sometimes a player or players gets jealous that someone os better at making characters than they are and so they accuse the more mechanically capable of cheating and other things to try and get the GM to boot them? I'm not saying it is necessarily the case, but it is still a possibility that any GM must consider.
This can happen and is an issue I deal with from time to time. I have a mixed group, optimizers and non optimizers and I've made it quite clear to my players that optimizing is not cheating. It's more of a style or taste issue. Some groups enjoy optimizing all characters, some don't. It can be difficult when you have a mix of both players, as you have to make both sides have a fun time. I'm a bit amused at all this talk of booting characters because I've played with the same group of people basically for 17 years since we started in high school. It's a bit harder in such situations to just boot someone.
But yes if arguing over optimization gets really out of hand, that gaming group should probaly split up. No one is wrong and no one is cheating, they are just two styles of play and it takes a lot of patience and diplomatic skills to make a mixed group of optimizers and non optimizers work.
The thing about optimization doesn't really have much to do with intelligence or the like. Only newbies don't know the main tricks of how to optimize. What usually happens is the more intelligent players read the books and pick the best combos. Then, the rest of the group watches what they do, copies it, and soon everyone knows the same tricks. Once you're at that point, it becomes a matter of if players want to restrain themselves or not. (Or the GM, but I prefer not to be that heavyhanded. I lean toward the non optimization camp, but I recognize that many players enjoy this type of play and trying to trample it out is a sure recipe for splitting up my gaming group)