I don't want to play the PC, which is the position I'm put in every time a player just says, "Can I roll perception?" or "Can I roll insight?" There's literally nothing there for me to use in my narration of the result of the action. It places one more thing to have to do when I'm already doing a lot. Now I have to come up with something like, "Bortak intently notes the body language of the vampire and sees signs of deception," rather than narrating what the player already described followed by a success or failure modification.
That's not my job. The player has one character to play and I don't want part of that job on top of my own already very busy job. I'm not going to slight you if you want to do it, but I'm not going to do it in my games.