I'm not sure I understand where this thread is headed. Maybe there have been some bad incidents in the Review Board that I am unaware of. Personally, I don't read or respond to those, so I think I'm speaking of criticism in general.
I have to be honest in saying that I have learned more from 'negative' comments than I have from 'positive' ones. Often, I feel more comfortable with criticism than I do with praise.
If we are just talking about models here, then I don't think people need to get too bent out of shape about harsh comments. For the vast majority of us, it's a hobby. We wont lose our job or fail out of school becase we didn't impress someone. So, I really don't see any pressure here other than to do better on the next model than you did on the last.
Usually people who are really good at something don't need to make themselves feel superior by trashing someone else. In fact, they try to be encouraging and share some of their knowledge. And, if they do point out a flaw they are the ones we need to pay attention to.
But, I do think my comment about being thick-skinned is a valid one. Sure bad comments can hurt, but so what? Sometimes life is a bit unfair. Look, we can't succeed at everything we do, why is building a model different? If a comment is bothering me, it's usually because there is some truth in it!
If someone quits the hobby because of a negative review, maybe they ought to be collecting baseball cards or beer cans instead. This is a hobby that requires some skills that may take some time to develop. Some will learn quicker than others.
We can all sit here and say 'build for yourself' and 'it's only you that you have to please' but we also know that's only part of the truth. We all see great models at shows or in magazines and wish we could build at that level. And, I'm sure we get down when we can't duplicate what we saw in Fine Scale Modeller. To me, that's part of the fun - trying to improve and get better at the hobby. If you keep building the exact same way each time and refuse to try some new stuff, where's the fun? You might as well be watching the same movie over and over again.
What I tell my students is to be wild and fresh. Try new things. Steal from what inspires you and take it to the next level. If you know anything about art history you begin to realize that art is a progression. Nobody reinvents the wheel. Instead, they build on what others have done and give it their own twist. It may take years to get there, but eventually it happens.
And, remember, they're a lot of idiots out there!

If someone is telling you that your shade of olve drab doesn't match this or that reference or that the position of a bolt is few scale inces off, so what? Tell them it's artistic expression...
Steve