It's rude to dismiss someone based on their issues.
Henry is a supervisor at a grocery store and has a shelf stocker with Down syndrome who isn't doing very well.
Henry wants to get the shelves stocked well.
Henry assigns another employee to work with the troubled employee and train him thoroughly.
Henry fires the employee with Down syndrome and hires someone else who can learn the job quickly.
With time, the mentally handicapped employee learns to do his job well and contributes to society.
The employee with Down syndrome never manages to find another job and feels terribly about life.