People play RPGs for a variety of different reasons, and care about each reason in varying proportions. Players may not even be aware of their own tastes, as it takes time and honest introspection to analyse such things.
DMing needs to be its own reward as it does involve more work than the average player. DM burnout is an issue, as creativity may not be infinite, OOC group tensions can rise, the game may drift in a direction undesirable to the DM, rules bugs may proliferate etc. But most players I know of appreciate DMing can involve work, and I suspect players would provide positive feedback to you if they were aware it was useful.
Myself, I cared about mechanics and rules first, so I can understand goal-oriented players trying to use the rules to achieve in-game success. Looking at RPGs as a game foremost, this is logical and makes sense. Using the most powerful options available and exploiting broken rules, similarly. I personally enjoy seeing my players use their brains to try and solve the world.
The downside is dealing with badly written, ambiguous or broken rules, and trying to balance things so the game is fun, when the rules themselves don't do so. (Incidentally, this is one reason why a lot of referees and players like better game balance in games, as it reduces the need for constant rules wrangling, cuts down on arguments and leaves more time for plot and story, the fun stuff).
Rules based player optimisation is based on the thesis that the rules are being used to resolve everything and maximising the "important" PC abilities will result in a higher success chance. If this starts irritating the DM sufficiently the thesis becomes no longer true, and it may require an OOC discussion about what the game is about. Such discussions may require compromise, or realisation that some of the players primary enjoyment comes from PC min-maxing, and yours doesn't. (this may or may not be the case).
As time as gone on I have grown to care more for plot and story than I did. Partially this is because my current players care more for story and plot and are less goal-oriented and more dramatic, so my game has drifted in that direction. Being a DM most of the time, I have come to accept that a perfectly realised gameworld is impossible and not worth the extreme effort entailed, and focusing on the elements of the world the individual players are interested in has a better return on investment.
Min Maxing players may not perfect fit players for someone who cares primarily for story and plot, the game working out in particular ways. Rules often don't respect the preferred story line.
Most of the problems I've seen in these games is due to the game designers failing to see a combination of abilities that creates a serious balance problem if run RAW and not bothering to design the higher level game with the same concerns they use to design the lower level game. It often feels like they don't playtest the game past level 10. It starts to breakdown because of the lack of testing. 5E has ameliorated some of this with compressed math. Past editions have used mathematical models that become unwieldy past level 10 or so.