The merit system itself is supposed to promote good posts; if members post good posts, they will gain merit, which then reflects the quality of the underlying post. Of course the system is quite new so it may take time for people to settle into it and get used to it.

As for the bounty programs, it varies by bounty. Generally people at Jr. Member and higher can participate, but those with higher rank simply get more stakes. An alternative might be to sign up to write blog posts &c. - real quality posts - which in some bounties gets rewarded additionally to forum posts.