As a member of the forum and you're not growing in knowledge of the main purpose for which the forum was created for then it's a waste of time and energy for you. The forum is not just about earnings so if your growth in the forum is focused in ranks you are basically not growing.
Without knowledge and good posts, you can not rank up.
If you rank up with your good posts, you deserve to be hired by campaign managers and companies because your good posts will help their advertisement through signature better.
Knowledge, rank and income exist and grow together and you will have better income when your rank is higher. Ranking up when your brain is empty is impossible and even you rank up without knowledge, managers will not hire you when checking your posts and see only no quality posts.
I do agree with you 99% that without knowledge and good posting you can't rank up but on the 1% I think we can leave that argument for another day.
But in this frame we can't say for sure that there are people whose level of knowledge about bitcoin definitely match with their rank but that doesn't mean they have no knowledge of bitcoin entirely. What I expect for people like that to do which am not an exception is to fire up the interest of reading and learning much more to keep up with their rank level if after examining they find they the knowledge doesn't commensurate.
More like advancing and pushing for more knowledgeable notes within the forum.