I mailed them based on a number of reasons: 1. Critiquing is an essential step of the design process, 2. They provided an email address at the end of the post, 3. I wanted to ensure that they weren't reinforcing their design biases that had emerged as a result of their 2 month drive to release their concept.

You're reading it wrong - it's blunt criticism, but it's also constructive. It's not fun to read this, but I find it a lot better than someone saying your X is awesome while thinking privately that it sucks.

I'm not sure it's intended as a face-smear; but even if it is, personally I'd prefer to receive direct communication with criticism than to find out later that there is a community mocking my work.