I regularly read (quality) content online and think "I'd tip for that". But there's no way of doing it. I could click the adverts, but I don't want to deal with lots of popups and I have no interesting in buying whatever they're advertising.
But I don't think good will is a sustainable source of income, or at least not one that will work in the general case.
When the journalism is good enough, people want to make sure it survives.