Once they realize that it takes too much effort for such a little payoff, the flood of shitposts (and new shit-topics) will stop, that's my guess.  These pajeets are not hard-working writers, nor are they creative.  There's no way they could earn merit with what they write, so there's no way in hell any of them are going to get any unless they purchase it or have an alt account give it to them.  

The merit system is still very new, and people are still playing around with it.  The pajeets will figure out that it's not the lucrative game it was just a couple weeks ago, where they could post any lazy shitpost and get paid for it.  Just be patient and this will work itself out.
I've noticed a lot of this when I was tagging shitposters.  There were a LOT of padded shitposts, and you could tell after the 5th word that the pajeet had exhausted its vocabulary and was just repeating the word "bitcoin" like a broken record.