It is quite clear that most competitions have fundamental flaws and I can totally undestand why anyone would decide to give them a miss. We've all looked in horror at the results of "The Nescafe Fine Blend World Photography Award Winners" and thought "Hang on, I've seen 10 shots in my favourite forum this week that are better than any of these!"
But I do think it is helpful to engage with other photographers and in this way, the internet is invaluable. Disheartening sometimes- there are many stunning images out there- but helpful, not least in bursting one's bubble when necessary. Often another pair of more experienced eyes will point out an aspect of a shot which one hadn't noticed. As long as the criticism is about the photograph, rather than the photographer it is almost always valid.