Half of the people on my list wold end up back on there in hours if I took them off, so why bother. Either they are extremely opinionated (and rude about it to boot), or they just rub me the wrong way for some reason, and Enworld is a nicer place for me if I do not see their posts. Yes, I could take the good with the bad and not use ignore lists, but it is just less stressful this way.
I can imagine having a thread starting at post 13 would be amusing. I've never had that, I think my record is 3 or 4.
One thing I have found odd is you can put mods on Ignore, which seems wrong to me. I tested it out a while back, but currently have no mods on ignore, nor would want to.