Even if someone doesn't specifically pitch an idea on how to fix something to you it doesn't mean their comments are flak. Criticism can be constructive and useful even if all it does is point out problems. How? Because the person that receives it at the very least can try to do the opposite of whatever is bothering people. If people have a problem with a character using several elements as a power you can infer you might want to try working with less elements if not a single one. I was constructive, I just didn't phrase everything as a suggestion or massively understate the problems I saw.
Pointing out that a character can physically disappear into his own brain leaving nothing behind and that his zanpakuto can predict the future isn't being mean. That's not nitpicking either. Is clarification really necessary on why such abilities are broken?