CONCLUSION: Don't search for merit, let merit come for you through your meaningful post.
I see this somewhat incorrect (as logic). One can search for merit and actually do that by trying to make very good posts.
Even high rank users are chasing merits sometimes. Some want to get to the highest rank there is (since it may bring more money from signature campaigns), some probably want to prove something (I don't know what though).
As long as this brings really good and useful posts, it's not really harm in that. The problems start when dirty tactics are used in an attempt to "rush" the achievements.
And one important thing that imho can be also mentioned even in this context is that reputation is important and it's very easy to lose it (and very hard, sometimes impossible to recover).
So even if one may be chasing merits, all he can do is to do his best in post quality and information quality. Any shortcuts can easily backfire.