I think it's frustration, really. People are getting tired of HQ saying they want to leave up some threads to educate, when there is obvious disablist language on it. I'd understand it if they said "okay, this is new, we're going to do this and focus on educating people for the next 3 months, then Bam! we start deleting." But it's not.
Six years ago, when I first was learning my son had disabilities, MNHQ was saying this. Six years on, it's still happening, so yeah, I feel it's kind of rubbish. Yes, I get that there are new people coming on all the time, but there will ALWAYS be new people coming on. At some point, HQ needs to step up and state that we're done educating in this regard. They don't educate for racism. They delete. Disablist language should be treated the same.
Perhaps on a second deletion, people should be automatically suspended for a week, you know, to give them a chance to educate themselves over whatever issue caused their posts to be deleted, be it racism, disablist language, or just being a dick (although I suspect that's hard to educate yourself out of 
).
I don't really know what the solution is, however, my feeling is that those that deal with disabilities and that are getting frustrated over the disablist language are feeling that there's been no forward momentum from MNHQ in years to contain it at all. Perhaps it might be helpful if MNHQ took note of that and took some steps to rectify that, as quite frankly educating people isn't working very well, especially with new people coming in all the time, and lately it has been a bit of a free for all. I think MN is walking a thin line between freedom of speech and allowing hate speech on the site, as my understanding is that as it is their site, they are ultimately responsible for what stays on the site (otherwise why the kerfluffle over that child care book author or the McCanns or Samaritan's Purse), and sadly, I feel that they often err on the side of allowing things to remain that cross the line in this particular subject when they would not do so in other subjects. And that is partly why so many are upset, IMO.
Or to put it more bluntly.... they are shit hot at jumping on posts that cross the line in certain things, but slack at the disablist stuff, leading some of us to think that it's a low priority and that they can't be bothered. If that's not the case, then IMO MNHQ needs to make that message clear.... not by talk but by actions.