Some players like to act like their character would act, avoiding some decisions/armors/followers not because it's the best way to play, but the most suitable path for the character they created. Their characters may have desires, fears, and so on.
Other players may approach the game as a completionist. You may wear the best armor at all times, always use the best weapon, master all the guilds, use any follower as long they look the coolest or are the best, and have no trouble making decisions as long as they benefit you. Their character is sort of a "I do everything" sort of guy.
I do role-play a bit, but probably not as much as others. Sometimes I'm the lowly thief who can hardly scrape by (mods that make you need to eat and stuff really make it fun). Or other times I'm a tribal warrior who's honorable but uncivil. I'd only wear leather armors and try to use spears (a spear and jungle mod really helps).
I think it makes things interesting, as you kind of stack the odds against your character. You find yourself having to do things in-game you wouldn't normally have to do, trying to figure out the best way to get around a new situation.