The question of how useful people with disabilities can be for their community and the society as a whole is a really debatable one. Much can be said in support of both "Yes" and "No" answers. Let me weigh up the two alternatives.
To begin my reasoning, people with disabilities can be very efficient workers in the fields that do not require the missing physical functions, such as, working at call centers, computer programming or craftwork. In the same way, people with disabilities can perform professional duties with the help of specialised equipment, e.g. using microscopes at the laboratories. Also, disabled sportsmen can successfully perform at Paralympic games and similar events.
Conversely, the potential of people with disabilities is lower compared to healthy individuals. Many of them have a poor eyesight or impaired hearing. To add, on average they are physically weaker to say nothing of physical defects. Last but not least, disabled sportsmen cannot do without artificial limbs, wheelchairs and assistive devices.
By arguing my case, if a person has poor eyesight or impaired hearing, it can be helped with a pair of glasses or a hearing aid. As for lack of physical strength, people with physical disabilities can be extremely useful with their intellectual abilities. Regarding the need of assistive devices, healthy people are using all sorts of equipment on a daily basis, such as cars, lifts and trolleys to name but a few.
As seen from the above, people with disabilities can do a lot of good for their community and a wider society if we all are more responsive to their special needs.