I don't agree. Rank of the member should mean his "seniority" not only by number of posts, but also by quality of posts. I think that nobody wants Hero members that are posting shitposts in this forum. So i like the idea that members should qualify for a higher rank only if they post something meaningful. If you are more interested in intellectual benefits, then there is no need for the rank upgrade anyway..
The other thing is that currently it's quote difficult to get some merits. It looks like a very long journey to upgrade from Member to Full Member for example, even for users that are posting quality posts. I hope this will get better once there are more sMerits available from Merit sources.
Yes. You are right that rank should reflect some form of quality as well.
However, if somebody just want's to be active on the board and does not care about gaining any monetary benefits, then they already have the inherent desire and thus inherent incentive to engage in higher quality discussions and would naturally avoid spamming the forums. If merits (for the purposes of rewards from signatures) are decoupled from ranks, then the ranks themselves hold no value for those who are interested in monetary gains, but remain an nice recognition for all others. Since there would be no other rewards associated with rank than a personal satisfaction and gratification, simple spamming would be just a waste of time.
On the other-hand for those who are primarily interested in using this as a source of income, and thus for those whose incentives can get misaligned with posting quality, merit system can provide the external "encouragement" to focus on quality and avoid spamming.
So, I don't think decoupling leads to a deterioration in quality. Keeping them coupled, however, could potentially stifle more active participation. Psychology and social recognition are strong forces here.