I think minmaxing is something that's not getting nearly as much discussion/debate as it needs in gaming and game design. It's something I've been thinking about a lot lately. I think originally the term came from P&P roleplaying games but the term now is pretty much exploiting systems and mechanics to maximum efficiency in any type of video game. While I can definitely understand the appeal and craftmanship in squeezing as much as you can out of something, I've come to realize that in the vast majority of cases this just turns into an unenjoyable, detrimental experience for me. Especially in online games.
I think my first experience with this was playing the first Starcraft online. As time went on, players became increasingly focused on micromanagement to get the most out of each individual unit. The influence of the competitive scene made micro so widespread that it basically turned into a completely different game for me. And I don't play strategy games to babysit every action of every individual unit.
More recently we have Chivalry: Medieval Warfare. While it isn't very common on public servers, I'm a bit worried this will spread to the general playerbase and make it unenjoyable for me. It's difficult to explain for someone who hasn't played Chivalry and isn't familiar with the melee combat mechanics. Basically the more skilled, competitive players have adopted these convoluted mousedragging mechanics to maximize their performance. It makes the characters look like they're spazzing out and having seizures. It's completely ridiculous and I very much doubt this is how the developers intended the game to be played (Ironically, these same players usually scorn other players using the basic feinting feature).
And then we have of course World of Warcraft. This is where my main issue is less with the players themselves and more about Blizzard pandering all too much to minmaxers when redesigning and balancing the game. This has resulted in a myriad of traditional CRPG features being removed or watered down. All because a select few players don't want to feel forced to switch to a certain race or class just because they might perform 3% better than their current choie in a raid. I would not be surprised if at some point in the future RNG/Dice rolls are completely gone with each weapon swing and spellcast doing the exact same amount of damage every time with no random chance of criticals, and every class playing virtually the same (getting pretty close with that already).
Last example I can think of is Torchlight 2. I was looking for guides on how to play Embermage, and I was pretty much told to spam one spell and one spell only throughout the entire game... I mean, seriously? I even recall watching a preview video with developer commentary, and he said himself that he prefered himself to play in a more casual manner without worrying about minmaxing. I can see why.