I am in no mood for it, but just because it is you:
Ok, I agree with a TB on 12-all. Half my resistance was just being a pain in the ass. But the arguments for the fifth set tie-brear, anyway, in general are weak ones. Statistically, it is simply not true that players who play a long fifth are toast in the next match. Of course Isner lost after that absurd one, but Anderson himself survived the 13-11 against Federer, last year Muller won 15-13 I guess against Nadal and went on one more, there are a lot of examples. It is just the completely off the curve cases that almost guarantee a loss. By the way, today Anderson's best set was precisely the third...
Why does it matter? Because it is quite stupid to change the rule for all based on what happens to just a few (and by few I mean basically just two, Isner Mahut and Isner Anderson. All the others for sure do not bring any statistical difference). So the 12-all is a reasonable middle ground, as we do not get too much matches that go beyond that anyway.
I do not buy much the "welfare of the players" argument. Again, people simply exaggerate things. I checked one thing you mentioned on the other post, that Isner and Mahut needed months to recover from that match: Isner got to the semis on his very next tournament, and Mahut got to the second round, and they were very early in the North American pre-USO wing.