I have a rather nuanced opinion on all of this... I agree with HalcyonicFalcon/Phyrnna in that we all started somewhere. I remember the first review I got on the first piece of trash I put up here when I was so excited I made notes come out of my computer speaker all on my own. It was constructive, critical, and definitely pushed me in the right direction. If someone wasn't there to do that for me, I probably would either have given up or would be still writing garbage. People who just begin really REALLY need to be given constructive critique and a big helping hand- tutorials, resources, even a friend or two on skype who can give them feedback and point them in the right directions so they can best achieve their own sound and style and find their inner self easiest.
However, I do feel that there is a need for people to put their BEST work as they evolve up. I don't put every single WIP and concept and rough cut... I put finished, well-rounded pieces up, or finished game loops that I feel are worthy of use and useable by developers, and I always have. Those first pieces I put up were my best and my greatest, some of them I even thought could be used in games (and some actually were, suprsingly). Sadly, I know a ton of people who just consistently throw pieces far their ability and lacking effort on the portal just because they can. Things like the two-a-day limit and scouting system are CLEARLY INTENDED to stop those people, but nothing really works aside from educating people in the need to really showcase themselves.
A lot of kids don't realize that the internet is their showcase. They have one shot under their chosen username to please or displease the entire world. If you mess that up, you may be waiting years until people start liking you. Many people also find trolling the audio portal by putting up false or poor pieces entertaining.
HFX- I do not think the OP's target is people who CAN'T write good music, but rather people who WON'T write to their ability and prefer to dwell well in the bounds of sub-mediocracy, refuse to reach out for help, refuse to try new things, and worst of all, refuse to take constructive critique in stride. These people continually do nothing but spam the portal and continually are allowed and accepted as 'artists' when all they do is detract from the very meaning of the word 'art'. Art is about expression and finding new ways of expression. There is nothing artistic about ignorance, hence the need for constructive critique mentioned above. I try to give critique to these people. Most of them, being trolls at heart, just laugh it off.