Listen to this great joke. Why are hospitals the best gardens? There's always a variety of vegetables to choose from.
What do you mean about hospitals?
That is where the disabled people are.
People with disabilities can be capable and it is hurtful to think they are like vegetables. You could become disabled later in life due to an accident or disease and you would not like it if people suddenly thought you were now a vegetable.
I think it's fine to describe the disabled as vegetables.
Just because you think it's fine does not make it so. You should volunteer to help disabled people to gain a better understand for them.