While I also feel somewhat alienated from all the 'innovation' that is occurring in the 'social space', I assume that Dustin does not, and when he thought 'this is a stupid idea' he was evaluating it according to his own measures of value, and by his measures of value, both vine and pinterest are great ideas. So, yes, he messed up.

But my own approach is to think that actually getting the energy to make anything in our culture that generally tries to separate the content creators from the content consumers is an amazing achievement, and I try to avoid diminishing peoples enthusiasm to make stuff even if I think it's dumb.