It is simple: if you have a lot of activity and no merit at all, you won't be able to rank out. It was made for the purpose of making activities more useful and to stop the possibility of ranking up to those whose activity doesn't have enough quality.  Nevertheless, there are several threads here where people are offering merit to those who create a good quality post. So, maybe, you can try to improve your posting activities and apply to that kind of threads. I always give merit to the people I consider that are making a great contribution to the forum. I don't care about the rank they have, but about their opinions, the information they share and etc. So just be patient and create good texts.