The notion that a disabled person cannot contribute to society is both foolish and based on old superstitions, a product of our fear of both differences and change. The reality is simply that no one wants to pay us a liveable income for what we contribute.
The other fallacious notion common, especially among those who are paid to actually assist us, is that we don't want to work. Many people have this idiotic notion that disabled people are as lazy as they are. This is demonstrably fallacious due to the fact that most of us are disabled because we were over worked and under paid prior to the disability.
Yet when we seek to change our situation we are greeted with contempt and hatred from everyone. Well, almost everyone, oddly the scientific community is mostly generous and easily the least judgmental portion of society. It is important to note that one does not need to work in a lab to be scientific, one must only comprehend the scientific method and not be a total idiot who asks "why are there still monkeys?"
Back to the topic at hand, disability is mistakenly thought as an inability or lack of desire to work, when it is actually lacking the ability to do a specific set of tasks due to a physical or psychological difference, making the person unable to function the same as others of their species. Fore example, Stephen Hawking, a genius who is unable to utilize most of our tools, you do not expect to make him flip burgers, but someone with arthritis of the hands is often called to do just that.
The flaw in society here is the definition of contribution, most incorrectly consider a contribution to be a marketable act for profit. Most of the greatest contributions to society offered absolutely no profit to those who have made them, and quite often resulted in their ridicule, discouragement, and even murders.
Many years after society has essentially destroyed them, removing the possibility of them offering more contributions that could benefit society as a whole, do we discover that not only were they correct, they just saved the lives of billions of their own species and never asked for more than food on the table and the right to live a healthy life. This is the legacy our species gives our offspring, even today.
As a species, are are fundamentally insane, for we create demons in the darkness because we fear lighting that candle called science we created to illuminate that cavern called life that we must all walk through. Instead we cling to the blindfold called religion finding a false comfort in the lack of answers offered by following the blind leaders who are looking only where we have already stepped.
To progress as a species we must now discard our notions of the importance of profit and excess, we must understand the true value of all contributions before we lose the sources for more. Look at those who face chronic illness, pain, disabilities of any sort, look closely as what we have to say, what we build and create, and what we discover in this ever darkened cavern called life.
I promise you, the cure for cancer lies in the minds of one who suffers from arthritis, they merely need someone to listen to them.