Being based in Europe, I deal with airlines farther along the curve in devaluing programs than those in the US. My response has been to fly price on intra-Europe travel, which often means LCC's. I still participate in ff programs for TATL and US domestic travel when I am in the states, and have never flown an LCC except on intra-Europe routes. Most of my intra-Europe travel is on LCC's. If the US-based legacies want to destroy their ff programs, then I'll do the same with my TATL and US domestic travel, and do my best to avoid the legacies.
The formation of a large membeship base in an associatioin of frequent flyers that influence people to move business might get some airlines attention, but I don't know that it would be worth the trouble to put together.
As to those airlines that want to shortchange on miles on cheaper tickets, I am a mixed fare flyer and always have been. Right now, business travel outweighs personal travel, and my business travel is out of higher priced buckets, while I try to get the best price I can on personal travel. But an airline that screws me on miles on my personal travel is going to lose my business travel, too.
I suspect as many airlines keep turning the screws, one will figure out that being a little more generous will way off big time in driving more business. I would suspect that airlines is most likely to be AA or CO, and least likely to be US or DL.