Interpreting my comment as "don't encourage anyone" is an extremely uncharitable take. Support their endeavors, celebrate successes, be empathetic of failure. Don't tell them "no excuse for you not to able to do that."
It's a sad state of affairs if the exchange needs to be "please share your situation with me so I can know if it's appropriate to offer words of encouragement" before offering words of encouragement.
Lets take an example of the most brilliant people of our time while also extremely handicapt Steven Hawkins.
What would he care he was excluded in a statement like this?