What are your thoughts on "playing bad" to better fit your character?

I don't mean this in the "it's what my character would do" sort of way. By this I mean taking things like worse spells or objectively worse subclass options just because it fits more with your character. I've had a few party members criticize me for certain choices I'll make with characters because "don't you know that such and such option is the best one?" and yeah sure maybe that's true, but to me I think the feeling of the character is what's more important to me than having the best playable one.

Also mildly unrelated but in a similar vein, reminding the DM of things or siding with decisions that actively hurt you in the name of fair gameplay. Some players seem to be in the camp of "Why would you help him out that's going to hurt you" but I believe in playing the spirit of the game, not just the most ideal outcome for me.

Thoughts?