A bit oversimplified with a huge dash of optimism:
If you give the crips a conference, they'll feel like they belong.
If they feel like they belong, then they'll start to network.
If the cripples start to network, they'll pitch and submit more.
If they pitch and submit more, they'll publish more.
If they publish more, they'll want another conference.
Ableds say: "Poor writers can't afford to attend conferences. It's not a disability issue, it's a class issue."
Employed people with disabilities make around 33% less income than their able-bodied counterparts. The unemployment rate for disabled people is almost twice that of their able-bodied peers. Class and disability status are often linked.
Ableds say: "A lot of writers don't attend conferences, and they are fine."
There is power in the knowledge you're welcome somewhere. Even if a disabled person had the time and money, they still couldn't go due to the lack of accessibility. It means we're forgettable, unimportant, or don't belong.
Ableds say: "Accessibility costs money."
So? Organizing a conference in general costs money! Are people complaining that they're paying for food or presenters? Most conferences are held in fairly large cities. Cities mean a wider choice of venues. More choice means accessibility can be considered, just like size or location are considered. Accessibility isn't even on most organizers' radars!
"If you give the crips a conference, they'll feel like they belong." It's not that easy, but it's a start. We're waiting.