I must admit to be updated on the last fisting scenes but I wouldn't be so negative.
Having seen some recent pro-am footage I am personally happy with the latest entries in the biz. I see more and more girls ready for the hottest scenes then I think it is just matter of time.
I mean, ass fisting is still an extreme performance but it was the same with DP and deepthroating few years ago.
Now actresses know that sooner or later these scenes come and they are ready for.
Just think to the anal... there are very few girls in the biz that wouldn't perform that. And I have personally seen some first scenes already including anal with almost no problem for the girls.
So I have to say that porn now is largely better than porn in the past.
For me it is a positive evolution.