Stuff does sometimes suck, but there's generally a way to make it suck less. I mean, I am personally not a fan of self-insert vampire novels. But more than a few have made their authors very wealthy, so if that's what's someone's into - hey! - more power to them! That said, there's a huge difference between "Twilight" or "True Blood" and most of the stuff that's posted for critique. (Generally incoherent plots, poor pacing, overuse of latinate words, etc.) So there are almost always of making things suck less, even if in your opinion, the general concept is a crappy one.

I tend to be more hands on. It's a different approach, but I'm generally a fan of trying to figure out exactly what the issue is and fix it. I see so many stories where the problems boil down to mechanics - the plot leaps about in a way that's confusing, the characters are inconsistent, there's too much exposition, there's a lot of needless stuff that slows down the story, etc. These are all fixable issues!

I'm growing to avoid the "OMG, this sucks!" stuff as I just don't see the point. That said, I feel kind of sorry for the poor would-be authors out there who are genuinely trying and just aren't there yet. I was there once (as were almost all of us), and it's fun to give tips. (Although, amusingly, it tends to be the better authors who are gracious and eager to receive criticism. Hmmm...I wonder if the two are connected?)