Why is it so hard for people with physical challenges to find jobs?

Because accommodations have to be made.

Most people can’t see beyond the physical challenges , to see what that great person actually has the offer them and there team , or immediately look and make assumptions of what challenges you might cause them in the workplace

Interviews require travel, and they expose problems unmentioned in resumes.

Because jobs require people to function normally perhaps?
No, that can't be. It must be a personal grudge against people with disabilities.