I don't agree that merit is just a matter of pride for legendaries. The actual count is not important to me, as I will never be able to compete with the stats reporters. However, individual awards are useful, and they give me a feel for the general opinions in the forum, and they help me to "tune" my posts and threads.
A lot of legendary members haven't earned their first 1000 merit so gives a good idea of a good poster if they have earned more than that. Legendary can also send that earned merit to others so its not like its being completely wasted.
I have no issues ranking up a newbie to a junior member and giving them signature privileges as long as it is clear to me that they are here primarily for the reason I outlined above - to learn and discuss - and they aren't here solely to abuse that signature.
Signatures should be something to reward already good and established members instead of being something people aim for. I don't change my behavior when in a signature campaign and despite being in one of the highest paying campaigns you will see that I haven't posted for a couple of days. My posting habits haven't changed just because I'm earning money from posting and I think looking at the before and after statistics when accepting members and moderating a campaign that should be taken into consideration.