It kind of baffles me how you think that telling someone what they made is 'cringe' and that it would look better in another style isn't an offensive statement. Even if it's 'just your opinion', it's pretty terrible to tell anyone something like that.
It's like if you walked up to a lady and said "Your baby is really ugly, so you should try making a new one with someone so maybe it'll look like that cute baby over there. That's just my opinion though." See how terrible that sounds? x3
Just have more tact when expressing your opinions next time, or try to be constructive. Constructive criticism or feedback is just fine in most cases (unless folks just don't want that). Or better yet, stick with the saying "If you don't have anything nice to say, don't say anything at all."