I don't think that's really fair. No one gets run off for trying to contribute. I made some mistakes when I was first starting out...they were pointed out to me with indications for why my scans were rejected, and I learned from those mistakes and endeavored not to repeat them. This site is a great resource, but it only stays one when the people contributing adhere to the standards the site expects.
Read the FAQ's. Make sure your information is as accurate and complete as possible. If you're not sure, ASK QUESTIONS. Remember, that the people fixing mistakes are doing so on their own time and without any compensation.
I don't know your situation or what has made you cynical about the site, so this is a more general observation: if someone routinely posts things that are against site rules (photos instead of scans, etc.) or need major corrections, it's not unreasonable to think that those trailing after and cleaning up the mess will sometimes get a little annoyed. We all have different levels of skill, equipment, time, and, yes, interest that limit how much we ccan contribute. All most here ask is that if you are going to contribute, familiarize yourself with the site standards and follow them to the best of your ability. When mistakes are made, report them if you are unable to correct them yourself, and try to avoid repeating the same issue. Contributing to the site in a way that causes more work for others is simply counter-productive.