Fish's response was "Your games just suck." It was an incredibly rude response. A lot of people don't like Fish since that incident.
It doesn't help that he's incredibly sensitive and rude in his public comments (that is, he seems to be able to hand out criticism, but not accept it with grace.)
At maximum I would call this a social faux pas. Certainly not something deserving of bullying.
If I were asking the question, I would actually value that response. Here's someone who is willing to be honest with me instead of using generic political speak.
Edit: You say "bullying," but I would suggest that he maintains his online persona in such a way as to generate controversy. He comes off as very abrasive, even annoying, at times. I felt that he specifically tries to spur such reactions with his comments.
"Cry me a river, Fishy-boy. No one cared for FEZ, no one cares for FEZ II and no one cares for the cancellation."
"Get lost you waste of talent. Shitbag telling others to kill themselves, you dont deserve your fame, money or attention."
"Good. I hope that you never come back"
"You are an embarrassment."
"Good news. Stop making games please."
I've scrolled 0.1% down the page but I'll stop there.
Doesn't excuse this behaviour at all. But Phil Fish is not the only one who has to deal with it.
The problem is that emotions definitely come into this, and you have to consider that you just belittled an entire country's gaming industry with the comment without at least expounding on it. Blow's comment was much better, even though he pretty much said the same thing.