How is it demeaning? I am usually brief and direct, but I don't call people names or discourage them (unless telling them they should use a different method is a discouragement). I only point out problems and ways to fix them. If I like something despite the problems in it, I say so.
As an aside, I'm curious -- I've lurked in other threads where you give advice, and I usually find that you are technically correct, but your tone is a little demeaning. I don't mean the difference between solid crit and an asspat, or anything like that. The difference is entirely in how you treat the person. Is there a reason for that? Is anything accomplished by that? Honestly curious.