I agree that would be great if designers put energy into helping non-profit organizations. But I think we miss the point:

Unsolicited redesigns aren't trying to solve any problems, they're mostly about training UI skills. And as said before in the thread, it's vastly easier to work with no real world constraints when trying to practice/show your UI skills.

Those people doing this type of work, normally have zero contact with the company, clients or users. Even when they present some type of research behind the process, it is frequently a very shallow research or with the wrong audience.

I don't think this type of work is valuable to most companies. Maybe one with a very simple product that wouldn't require any contact between the designer, clients and users.