Rich,
I like to think that I am the first to chastise criticism without a reasonable alternative being offered. With that in mind, a few thoughts on this:
Very good point. Which certainly means there will be a balancing act necessary in order to accomplish goals that may be a cross purposes. The trick will be to allow someone enough rope to allow them to show everyone that they NEED to get hanged BEFORE the posse takes them to the tree to help them along their way.
It is hard to qualify the plan without knowing the actual parameters, but with the above highlighted section, "everyone" would seem to be quantified as "enough to comprise the empowered lynch mob". If, on the other hand, the power rested with a process that had more merit, then a self-purging facility here might accomplish its goal. Without citing specific instances here, there have been Fauna "mob hits' that have harmed innocent folks in material ways. Some have been corrected with minimal damage, and some not. I would be glad to share a few examples with you in private.
I believe you are suggesting a means by which posters could be stifled, for good reason or otherwise. Whatever the final new criteria, you had posters here in the past who rightfully (by your criteria) earned a trip out the exit door, and yet you then decided to let them back in. To no one's surprise, the WWW got more WW_ .
It is no secret that the drama and scuffles create hits and traffic for the site. If this proposed change has traffic as a goal, or more of a goal than quality, then quantity may increase again, with quality taking the hit again. It may be an excellent business decision in many ways ....
Of course, if it proves to be the case that the greater majority of people forming the "mob" are the kind with just the detriment of this site at heart, maybe that will be rather instructive in itself. If the "good guys" here will allow that to happen, then who am I to intervene?
... depending on how one quantifies "the detriment of this site". Why not just empower the "good guys", as you acknowledge they exist

Pick 10 of your best who seem to have always avoided being part of a mob, while still being active participants in the site. Just a possibility, but give them a "bomb" as suggested earlier, such that 3 or more of them can exercise collective power. Maybe 3 hits from them in a seven day period, and the poster is suspended from posting for 7 days. Here's some names, just as examples: Dan G., Mike G., John S., Laura F., Jim O., Seamus, Lucille, and there are more. I have tangled with every one of them, so I do not believe I am attempting to stack the deck except to say that these folks are fair. Obviously I have excluded some frequent posters who always seem to be part of the mobs.
