It depends what you say and do. If you (not aimed at you personally) post to provoke on topics that are inflammatory with the intention of upsetting posters for whom the situation is actual real life then yes, you're a troll and you ought to be booted off MN. The premise is 'for parents, to make their lives easier'. How does heckling and goading achieve that exactly?
I could say I don't like the thread or hide it but why should I? This isn't anybody's personal playground and if you want that freedom, set up your own site. If it were permissible to post like a troll the threads wouldn't be deleted would they? I'd be very surprised if they're deleted on one poster's say-so and, when I've received an e-mail from MN about a deleted thread it's usually prefaced by "Sorry for the mass e-mail". Which means that there has been multiple reports.
From my experience, the vocal dissenters are up front with their views but it doesn't mean that there aren't other posters who agree but don't want to put themselves 'in the firing line', which it very much is.
I personally don't think it's ok to 'walk on by' when there are disgusting posts about paedophiles, disabled people, SEN children and any range of emotive subjects; some people clearly do. I know that some posters do enjoy these and get very much satisfaction from starting and contributing to them with the more upset caused the better in the name of 'entertainment'. If this weren't the case these threads wouldn't receive a single post and would drop off the page unacknowledged. I don't care what your personal trigger point is for requesting deletion or not. It's not for you or me or anybody else to decide what's deletion-worthy or not - individual posters make their own decisions whether to report and it's MN's call to act on the report(s) or not.
I'm quite happy to have a robust discussion and will disagree with posters on one thread and agree with them on another. I don't name-change or curry favour with any poster, I just have my own views. I disagree with you that there wasn't 'victimisation/bullying/trolling/goading on the 'judgemental' thread and the 'vindictiveness' one as well, it was horrendous. I don't know why you think posters' 'freedom to express' themselves trumps other posters rights not to be picked on/ridiculed/heckled, etc. but again, if you were correct in your assumption the threads wouldn't be deleted, would they? And they are being. Not by posters disagreeing with you but by the board hosts.
The 'freedom of speech' door swings both ways. I hide more threads than I read/post on and I don't report many threads at all but if I see somebody being a spiteful goady-fucker thread/post then I'll report it. You're free to not report if you please but you don't get to tell anybody else what to do.