Print competition is a valuable step in your learning process.
Entering print competition itself is a learning experience. It teaches you discipline and helps you refine your operational skill set in the same way a commercial client would have you shooting a job on "spec". You have to follow the rules.
Really examining the work you enter and deciding on composition, cropping, manipulation and even the name of the prints come into play. Is it good enough to demonstrate your very best work?
Then there's the experience of actually attending the judging. At conventions where it's open to the public, I'm convinced there's no greater educational experience. Just listening to comments from the judges will help you with ideas on printing, exposure, composition and most important of all, impact.
But a group of judges who didn't find your submissions as wonderful as you did means nothing about you as a person or even as a photographer. Take their comments as good solid suggestions. Implement them when you agree and ignore them if you honestly don't, but don't let your ego run amuck!
My image, "Koi" never did well in competition, but that doesn't take anything away from how much I love it blown up to a 20x30 and framed over the fireplace in my home!
The bottom line to how good an image is still goes back to my favorite timeless one liner from my old buddy Dean Collins over 20 years ago:
"Beauty is in the eyes of the checkbook holder!"