I don't think it's a terrible thing to offer suggestions when it seems that recurring problems are self-inflicted. But if the person refuses to listen or see their own role in the issue, I think the thing to do is to take it to PM or ignore.
I'm torn sometimes, though. I've been here for a few years, so I've noticed a few posters have habits and ways of thinking that keep getting them into bad situations over and over again. But if I didn't know that, and I came here as an outsider or newbie and saw a dogpile in the hugs folder, it might make me apprehensive of continuing here.
On the other hand, it's very frustrating to see newer people getting caught up in someone's sad saga and investing emotional energy in someone who will likely be back in the same position in two weeks. I try not to get too invested in people on the Internet myself (groups as a whole; I've formed pretty strong friendships with individuals), but it's hard to be any kind of community without some level of trust and support. I think repeat offenders damage that (compassion fatigue), but I also think jumping on people without some explanation or gentleness--even if you feel it's not warranted--makes for a hostile environment from a newbie's perspective.
I hope that all makes sense. It was a jumble in my head, and it seems only slightly less jumbled now.
ETA: By "gentleness," I don't mean "coddling." I mean speaking hard truths while aiming for a kind tone and some diplomacy.