We have to do something to improve the level of discussion here.
I believe that there are two reasons for the low-quality posts:
1. Adoption is growing exponentially, so most of the posters are still newbies, even after 6 years.
2. Signature campaigns motivate people to post even though they have nothing to add.
Some possible solutions:
1. Limit posts per day based on position: from newbie getting 1 post per day, to legendary getting 100 per day.
2. Disallow links in signatures.