I know several people who swear as often as, if not more than, this game. If you think this is a lot then you're pretty sheltered.
If you're offended, then yeah you're probably sheltered. But the amount of cursing in this game is highly noticeable and at times even awkward because it doesn't serve the purpose of profanity which is to heighten the feeling of emotion. Heller just starts sprinkling it in like he has some sort of quota to fill.