I have certainly seen a number of them like that over the years here, ez, but as Ann said above, conversation here, as in real life, ebbs, flows, evolves.
As long as the thread stays away from personal attacks on other posters, or the OP's or other's thoughts are not mocked and ridiculed, most often the thread should be allowed to naturally evolve. Threads that do get into personal attacks or mock and ridicule, should be closed. If the moderator folks on the board are not aware of them or not around, they should be made aware of them through the
Report this post to a moderator link which is on every post on every board. That email alerts all the moderators of that particular board, the webmasters and Pete of that thread/post. At least they become aware of a potentially (at least in the mind of the person doing the reporting) that there is maybe a problem evolving. I report one every so often, and most often they apparently agree as they are often closed or a warning is given. One just last night in fact here on the CB. It's sort of like 'Neighbor Watch' in our own real life communities, neighbors watching out for the welfare of other neighbors.
I have seen threads here on the CB clearly evolve into a heated back and forth debate, no longer really appropriate for this board, but simply having evolved into a classic debate. Those should be moved, IMO, to the Debate board then, that is what it is for. As long as the thread stays within guidelines there

it should remain open there, closed if it goes beyond guidelines there, (whatever they are there, not really sure, as I never go there). In recent times, I have most often seen those type of threads also closed, not moved. I think some of those threads still have some good 'life' and value in them, if given the proper environment, the Debate forum.
The main thing that always gets my dander up is when posters, any posters, are picked on, ridiculed, taunted or mocked. Drives me up a wall!!!! We are adults, let's act like it.
Long reply there, ez, but really a concern of mine always. 