Blue
Ravenous Bugblatter Beast of Traal
I agree, and I'll take it a step further.Optimisation isn't the problem. We all do that. It's over-optimisation when no one else at the table plays that way. I had this problem years ago during 3rd edition D&D. We had a player who over-optimised to the point that he was leaving everyone else behind and refused when asked by the other players to back it down to the level that they were comfortable with and preferred. The GM either caters to that player/s to the detriment of everyone else or they don't, and the player/s in question dominant and spoil the game for everyone.
In my experience, if everyone at the table is on the same page where optimisation is concerned, then it's all good. It's when one or more overtakes and then you have a problem.
When a player intentionally builds a character significantly more or less powerful than the rest of the group, they are introducing a problem.
(Caveats: this is about games like D&D where character balance is an issue, which is not true in all RPGs. Look at Marvel Heroic Roleplay. Also "problem" means just that -- something you need to workaround or fix, not something that you can't overcome. So please "but a good DM can handle that" is just reinforcing that it's a problem that needs to be handled.)