I suppose that's why Theymos took it a step further by removing Newbie signatures entirely and demoting Jr. Members who haven't received merit. Now all those farms of Newbies and Jr. Members have no incentive to post garbage. They have no signatures.
It at least forces the costs of spamming higher. Spammers either need to buy merit -- which is in lower supply now that the initial airdrop is long over, so it should be harder to get for shitposters -- or they need to buy a Copper membership for 0.002+ BTC.
Are the costs high enough yet? Maybe not, but I think we should wait and see. In my own observation, the forum's been getting more readable now that the merit system is established. I think that trend will continue under this policy.
There are certain threads that still are a spam fest, but there's less of them in general than before. Many potential spammers and farmers got wrecked by trying to merit their own alts or buy merit and that definitely levelled the playfield even more than the merit system itself. There was (and still is) a lot of sold accounts that were eligible for signatures and they didn't have to worry about getting merit.
The situation would be much better if somebody were to deal with all those hacked accounts that are being traded.