Oh fercrhissake. Yes, yes, of course if you have a completely incompetent instructor or there is some extenuating circumstance, perhaps, but let's not get carried away with being PC here.
If a student has a reasonably competent instructor in a reasonable time frame, I don't think we should call him or her 'differently abled' or 'special needs' if they can't get to solo in 80 hours. Instead, I think we should call them 'unsuited' and advise them to stop wasting their time and money.
Not everyone can drive a car, fewer can drive a fixed-wing aircraft and fewer still can drive a helicopter. That's life.