He's not bitter. He ends the post with: The conference was great, I had a good time. It's a really good starting point for even better conferences going fo

He's not bitter. He ends the post with: The conference was great, I had a good time. It's a really good starting point for even better conferences going forward. which definitely sounds positive to me. If anything, his reflection is a mild critique of things that could be improved, and is seeking to understand the community and how it sees itself.