I would say yes. There needs to be something to reflect "skilled characters" and something to put down ahead of what (generally speaking) "success" means.
In certain systems (mine), it's assumed that, to paraphrase 'Complete Scoundrel' - everyone has skill. And everyone can kill people, too. So anyone specializing in skills to the detriment of their combat may not really be of value to a party in the long-term.
The problem with lacking rules is that making it purely a subject for DM judgment puts a heavy burden on the GM, especially when a player is more (or less) charismatic/socially adept than their character.
This is my biggest concern, right here, when you get down to it. I'm not worried about those who are more socially adept than their character, I'm worried about penalizing those who are less so.