Yeah, I definitely think a certain amount of minmaxing makes sense. It's what people do in the real world: someone learns a lot about how to play hockey at the expense of learning political oratory, or they study ancient Sumeria while neglecting to learn how to change the oil in their car, or they learn all about computer repair but never quite get the hang of firing a gun. Everyone knows what a jack of all trades ends up mastering, and I kind of expect players in my game to do some level of minmaxing like this. It makes it more fun when each character has a special thing they can do better than anyone else, IMO.
Where I get frustrated is when people find ways to go beyond that: when someone finds a way to do their special thing better than anyone else does their own special thing, especially when they do it by exploiting loopholes in the rules, by trying to use poorly-designed rules, or by taking rules from multiple sources that were never designed to work together.
Daniel