Even without physical disabilities, many have a hard time with JPs because of other factors. "Try harder" is a very condescending statement. Those who are here probably have tried countless times and are very frustrated. If they haven't "try harder" and been defeated again and again trying to get the achievements, they wouldn't be here posting in threads such as this.
It would be good to have a Noob mode where the platforms will not disappear, but the progress will be 1 or very limited, instead of 20. Or double the time before the platforms disappear but you'll only get10% or 25% of the regular progress.. I'm sure many fail repeatedly because of the anxieties over the disappearing platforms, and no matter how hard they try, they just can't overcome this.
Another frustrating feature for those having a tough time with the JP is the waiting. Hard enough trying over and over again, but forced to wait to retry, just made it doubly frustrating .