1) It will not decrease shit posts number, may be even increase it. Why? Simply because new merit system doesn'trestrict anyone from posting and only fews trying to gain it, while all the rest don't give a f :)ck and keep generating tons of posts.

2) Why do new users need merit? To be available include well-formatted links to their signatures and to participate in signature campaigns. And who can give merit? Those users, who already can participate in campaigns and just are not interested in growing competitors for them by their own hands. So what do we see now: 90% of merit being spent on posts, which aren't in need of merit (e.g. https://bitcointalk.org/index.php?topic=3232693.msg33646534#msg33646534 ) and that doesn't mean there are no eligible ones.

3) The guys (mostly that are already who have enough merit to take a bath with it) who saying something like "it's not hard to be exceptional poster and get merit" - all of your merit is gained by exceptional quality posts..?