I have multiple entire sections on ignore, not to mention my extensive individual member ignore list, so I'd say the problem is still pretty bad.
When the merit system was rolled out in January, it definitely seemed like a lot of people were trying to improve their post quality, but since then it seems like the shitposting problem has returned (it never disappeared, but maybe it was taking a piss break for a bit). There definitely need to be some improvements to the system, and I'm pretty sure that if Jr. Members with 1 merit continue to be allowed to join signature campaigns, nothing's going to really improve.
For a while, there were some campaigns that had merit requirements to join, but that faded out. There used to be SMAS, but that also fizzled.
I believe that its improved the situation, but hasn't completely solved it. There's definitely an increase in the number of users actively trying to post good content. But, its okay if not all posts are top quality. I do agree that jr member signature campaigns or even low ranked members joining campaigns such as members is imposing a problem, because it's so easy to earn that merit. However, I very much doubt theymos would implement any kind of restriction, and I the projects advertising don't really care about the quality of the forum only their project.