Autism advocacy and the awareness campaigns lack effectiveness due to how closely it resembles the backwards historical traditions of most disability advocacy. Unfortunately, Jerry Lewis's approach is not the exception. He's just more vocal and less guarded than most.
If people who need more support and accommodation than others can be provided that by any means necessary (in other words, more public policies regarding disability are treated more favorably), it's possible that can lead to some of them having more opportunities for education, jobs, property, healthy relationships, etc., which can then lead to them having a healthier self-esteem.
However, if instead people's self esteem is the top priority and all efforts for helping them to attain all those things include never sacrificing their dignity, there's a good chance that the public will change many of their negative misconceptions about them, when the help comes it will be the most appropriate type of help, and they will be best able to utilize the help given. Most importantly, when they face setbacks and even failures (as everyone ultimately will) it won't be so devastating because they have more trust in humanity and belief in their sustainability.
When people feel accepted, dignified, and empowered lots of opportunities are visible that otherwise wouldn't be. When they don't, opportunities have little significance and nothing seems to matter much anyway.