I don't think age has a lot to do with it, you don't need to get the appeal to understand that it's at its core a payment to support or show appreciation to the entertainer. Even the Kotaku article linked in that particular thread lays on why a lot of streamers keep tips open even if they hit some comfortable strides of stable income otherwise. It's a short, volatile, fickle "career" (regardless of my grandpa notions, it's objectively a real job) after all.
And while I do think it's a payment system with a lot of baked-in perversions (and that it would be fairer and more sustainable under a more traditional organisation), the moral catastrophism feels more a reactionary pose with how constant it is. In a way, it proves a lot of people can be overly generous if predisposed favorably and accepted the usage of using the most direct way of financial support with as little middle men as possible. Sure, it would probably make a bigger difference if they did it for short circuit distribution of foods and goods rather than person playing a MOBA but heh, baby steps.
