I have 53 people muted. 45 of those users are spammers. Of the 8 people that aren't, 1 has left the site permanently. 6 of the remaining users are disruptive. The last one's informative and helpful, but I can't stand them, so in they go. I think that users should use the tools given to them to make their experience on the site better.
How do you see so much spammers? I barely see them.
I came across one user who I would classify as a spammer, a lot of their posts were in capitals and it was coming from the same three domains -- I use an ad-blocker but the design of the sites and the non-ad elements have given me a pretty clear idea of how it must look otherwise. I have muted them but it was a tough decision, as some of their posts do actually have interesting comments on. The winning factor was it's a topic I'm generally uninterested in and their articles don't do much to change that.
The first for all of them, often both. Note that it's not just that (there's plenty of people that hurt the conversation on here), but also if what they do give as input doesn't counterbalance their dickery. That's basically a judgement call, but I like to feel like I'm not missing out on something from them before I mute.