They do this to deter scammers. otherwise they could just create an account then post, scam, get banned and make another account.
I know that. Posting on a thread to ask a question/vouch isn't related to scamming though. People still add/PM you regardless. I understand not posting a thread, this means scammers can't post scamming threads for a lil while longer but the whole no post on thread doesn't stop anyone. We're only seeing not many very new people scamming people who have feedback thanks to MM's/them going first.
All in all, I believe we should keep the limit for posting threads, I don't believe we should keep it for commenting on them though.
@raze, spamming is posting for post count lul.
If we allow them to post it just re-creates the problem. The whole point of the limitation is so they can't conduct things in the market. Allowing them to comment on threads would allow them to transact.