I'm always baffled about this as well. I keep the people I follow heavily curated, and I don't follow more than 90 - 120 people at a time. Unfollowing and Refollowing is easy, why should I amass a list of thousands of follows like some people do?

If I notice a negative pattern or drop in quality I simply unfollow, that's it. It's the big advantage over Facebook, the relationships are not bi-directional for me as an average user.

In short: I get a quality experience and lots of useful information from Twitter because I only follow people that tweet quality content and useful tweets.

However I do have to mention that the algorithmic timeline IS really bad, so I do feel like Twitter is constantly fighting me and trying to turn my feed into polarizing crap.