To be clear, I'm not suggesting sources should be banned or not allowed to post on Meso. I know some feel that way but I'm not one of them.
The problem is with start-up sources. It's those sources who are responsible for turning the underground into a circus and trying to vet them is pointless because history has shown that almost all of them are non-viable. And they are too high-risk. Giving new sources a chance by complying with the SCOC has only encouraged more of them to come. However, they are still free to post on Meso as far as I'm concerned. As long as no one uses them, they probably won't stay long anyway.
I don't have any objections to well known sources maintaining a presence on Meso and if people want to buy from them, have at it. As we've seen, there still no guarantee their gear is good but they're not likely to scam outright.