When I read a critique that could roughly be summarized as "I could have done better" my response generally falls somewhere between "you should" and "I'd like to see you try".

Not everyone understands just how hard it is to create something from nothing, so I can excuse a certain level of ignorance in a critic. But I find it very disappointing when a critic does understand how hard it is in their domain, but isn't able to transfer that understanding to another.

When I think of critiques, I often thing of this quote from the book "Art & Fear":

  Writer Henry James once proposed three questions you could productively put to an artist's work. The first two were disarmingly straightforward: 

  What was the artist trying to achieve? 

  Did he/she succeed? 

  The third's a zinger: 

  Was it worth doing? 

  Those first two questions alone are worth the price of admission. They address art at a level that can be tested directly against real-world values and experience; they commit you to accepting the perspective of the maker into your own understanding of the work.