Personally, I find two things show professional dedication: experience/knowledge and the ability to laugh at oneself; in the majority of cases the latter carries the most weight for me. I say this not to underscore once again what everyone here is saying, that the reviewee should act professionally and quit childish "it's my toy" reactions, but rather to point out that the reviewer should, too. Although in the majority of cases, these reactions come up in reviewees, unfortunately I have seen them crop up in reviewers as well - who insist on questioning issues that nobody cares the least about (because they are simply irrelevant); who seem to get a power-rush from being in a position to show off how far and how deep their Vision cuts (although it may appear pathetic to the rest). Curiously, when you poke at them there, their reactions are exactly the same as those of the childish reviewee: they throw a tantrum or blacklist you. Hence, I'd say that "the attitude" holds at both ends of the reviewer-reviewee relation. It means being as brutal with oneself as one is to others, in the same measure as one is able to fondly laugh about oneself as about others.