It was the best route to get folks to understand segregation fast. Civil rights and women's rights had a clear history. Making the transition to rights for people with disabilities became easier because we had the history of the other two.
It is very difficult to get legislation passed. But then the danger always is that you have no power at all if you do not exercise constant power.
The first place to start is on enforcement. We who got the ADA passed did the hard part, the heavy lifting.