Games where the optimal strategy isn't fun.
I had that problem when I tried to play Elder Scrolls Oblivion. I was having a great time until I read an article on how to level "Optimally". I then couldn't play without making sure I was getting the full benefit every time I levelled, and then the game lost all of its appeal.
Same here, although I did enjoy spending several hours levelling optimally and designing incredibly OP magic spells. Getting those 5/5/5 level-ups was like scratching an itch. It wasn't adventuring anymore, though, just reveling in gaming the system.
My pet peeve is unskippable startup screens. I finally gave the remastered Spelunky a go, and it takes much longer to actually get into the caves each session. Kinda bad for a "hop in and play" game like that.
I just checked and it's nearly a full minute of spamming Z.
5 second ESRB screen,
5 second Mossmouth logo,
skippable walking-through-the-desert screen (which is the only one you might not want to skip, since it randomly generates a brief monologue!)
5 second torch-lighting cutscene to reveal "Press Z to begin"
10 second cutscene of a stone head rotating and sliding into the ground to reveal the actual main menu
Spam Z to select Play Game, Adventure, select your character, confirm that all characters are ready because apparently there's co-op
Two 5-second cutscenes of climbing down the rope
Run over to the cave entrance and enter
10 second cutscene of a spinning glyph saying "The walls are shifting", then a 1-second long loading notification in the bottom right.
Don't get me wrong, all this stuff looks cool once (and once you die, there's a quick-restart button which gets you back to playing a new level with no delay). But I usually want to hop in and kill 15 minutes on this. Spending nearly a whole minute on unskippable scenes seriously discourages that.
Games where the optimal strategy isn't fun.
I had that problem when I tried to play Elder Scrolls Oblivion. I was having a great time until I read an article on how to level "Optimally". I then couldn't play without making sure I was getting the full benefit every time I levelled(which was fairly complicated), and then the game lost all of its appeal.
Same, only with Morrowind. It made me quite glad to find and obtain mods that changed how the characters leveled up, so it was more intuitive and less contrary to regular gameplay.
I never understood that: why do you need to be optimal? Especially in a game so easy to cheese in. Half the fun was trying to get somewhere you shouldn't be at your level, and beat it legitly. And as poor as everyone thinks the combat was in Morrowind, it prevented combat chesse like you can do in Skyrim and to a lesser extent Oblivion.
The idea of "wasting" stat points forever just... bothers some people (like me). It's not like the game was hard to complete, it had a difficulty slider and yeah some exploitable AI. Not to mention custom spells.
It's probably the same reason some people hate it when a colorful mineral vein cuts through one of the rooms in their fully pre-planned dwarf fort. A very slightly above average rating on the asbergers spectrum, I think.