I talked about this one other time and was told, can't remember who it was, that PMs are for carrying on a private discussion over something that comes up in a thread which is not germain to the thread as a matter of courtesy to readers of the thread and nothing more.

BTW, the situation I observed last night is a tad more complicated and perhaps it can be discussed down the road in order to gather opinions and remarks which are more of a general and simple nature for the time being.