I don't think it's specific to HN, no. People have always been optimistic about their own products. You pour a big chunk of your life into something, and it's tough to imagine it failing, even if you know the competition has a leg up on you in some respects. One example that comes to mind is from Panic, makers of Audion, a shareware MP3 player that was killed by iTunes. From a conversation with Steve Jobs after iTunes was introduced at MacWorld Expo 2001:
"Well, Steve, I really think it'll still find an audience. We've got a lot of higher-end features that you guys probably won't ever add." [1]
That from someone going up against a free program that would be preinstalled on every single potential customer's computer. I can't speak from much experience, but I imagine that most people have trouble seeing the markets around their own software/customers 100% clearly.
So I wouldn't be too quick to blame it on the startup echo chamber of people wanting to keep image positive for VC fundraising. Nor do I think there's much anyone can do to change it. When people talk about their own products and how they stack up against the competition, you just have to take everything with a grain of salt and form your own opinions.
