For one, a main goal at any competition is to get feedback. Especially critics on the things that were not good. A competition like this usually nets you at least a few people playing your game and they will tell you what's good, what's bad, what's missing, etc. in a constructive way.
It's easy releasing a game out there, but do you get valuable feedback beyond "it's cool", or "it sucks"? Neither of which is really helpful in bringing you forward.
Read the feedback; do not interpret it as personal attacks. Instead try to see it from the players point of view. Maybe everything wasn't perfect, maybe there are things you missed or were not explained properly.
I see lots of entries in other competitions (e.g. Ludum Dare) where people make something, upload it and never seem to care again about their game. Which seems to me as wasted opportunity to grow.