I must admit I dread going near the place these days. I recently persuaded a client to hold a meeting online rather than have a physical meeting in the States. It saved me and others the grief of the MAN experience.
I think the only way that the owners will do something is if those of us who are members of FF schemes (particularly elite members) write to the airlines concerned and say that the experience has become intolerable.
MAG famously don't think of pax as customers (which is why they don't care about the pax experience) but the airlines and concessionaires as their customers. They will listen to the airlines.