A copy/paste of my response to HelensMumsnet post in my thread regarding 'hide poster', because I think the arguments are very relevant here, and don't want to retype the whole thing when copy/paste will do. 
Thank you for your substantial and considered response to some of the concerns raised here.
I would like to respond to some of yours (obviously just from my personal perspective).
I categorically would not have used the hide poster button to hide those whom I disagreed with... as, as you say, that rather ruins the whole point.
I would have used it to hide the posters that you eventually got around to deleting yourself (not your fault regarding the delay, I know), because they were not helpful in any way, and were simply rolling about laughing at what was for me a very painful issue.
If it happened in a thread about someone helping a rape victim, and people were posting making jokes about rape, everyone would be up in arms.
Everyone would be up in arms because they would 'get' that it was a serious matter and not something to be laughed at, and that laughing at it would be a cruel and vicious thing to do in the context.
I understand that people genuinely didn't 'get' I was serious, and I did report as quickly as I could. I just wish I could have hidden those posters in the meantime until you could have got around to it.
I would have had to see one mocking message from each of them, and then no more (which would have better than being bombarded, from my point of view, with them). I also wouldn't have had to see them again and again every time I went back to review the thread for better insight.
Let me clarify again, by "mocking", *I do not mean disagreement. I mean "haha, isn't this funny, lets make a joke about the whole thing"... right in front of my face on my thread. That really hurt.
I'm not asking for more policing. I'm not asking for censorship. I'm asking for the individual ability to hide posters continuously posting things that really shouldn't have been there in the first place, and cause distress the longer they are left up.
I don't want to have to go elsewhere. I want to stay here because the site is a breath of fresh air in my life. I'm not asking for huge, sweeping changes. I'm asking for a viable small one (in my opinion), that would have seriously helped me, and therefore can feasibly help others like me, and empowers me to stay despite my own weaknesses and flaws.
Once a poster starts laughing at you, and refuses to stop despite pleas. Its unlikely they have anything further of worth to say, and I would like to hide all subsequent posts from them.
I know people think I should have just hidden the thread. But there was genuine help on there, that I wanted to see and take on board. I didn't want to abandon the whole thing.
Not least of all, because that means the bullies have won.
Regarding the other concern (which is that people might simply hide instead of reporting).
How about when an individual presses the 'hide poster' button, a little pop-up reminder asks them if the post is also worth reporting?
Just an idea, as you can probably tell, I feel very strongly about this, and am obviously not alone.
I really appreciate that you are seriously considering it.