"Don't encourage anyone because they might not be able to do it" is the shittiest and most toxic attitude I've ever heard.
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?