I can back this up. It's well-known that Fox is not a nice person. See [0] for previous discussion, or just browse around the old TT-RSS forums (warning: some mildly NSFW stuff there).
edit: Regarding your edit, no, it isn't a language barrier. He's quick to insult people and treats feedback/contributions as opportunities to feel superior or meme (e.g., [1]). It's like talking to 4chan.