Sure there is. Let's say you flop a set with, say 77, on 5h6h7d. Table is loose passive, four in the hand including the big blind, and it checks to you on the button. Pot is 400. How much are you betting? The answer is at least 200, and I'd be going at least 300. Anything less is just stupid. You're giving too good a price for drawing hands to get there.

In the hand posted above, it's not quite so clear. I'd go half pot, expecting calls from Ax and pocket pairs, while his KQ and worse folds. Maybe we can get a call from the likes of KQ when we bet 4c, so maybe this isn't such a bad bet. But there are definitely times where a bet is obviously too small.