I agree that Wikipedias donation banners are very aggressive and the whole "Wikipedia has cancer" idea certainly seems plausible.
At the same time does any other top-10 site have a non-profit motive?
At the same time does any other top-10 site have a non-profit motive?
I think scaling donations is difficult. Wikipedia makes hundreds of millions of dollars a year, but its closest competitor, Google, makes hundreds of billions of dollars. But to the average person, a hundred million dollars is a hell lot of money. So people get cynical.
Also it's possible that donation models just don't work well. Dwarf Fortress is one data point. It was decent money at $15k per month, then people dropped 7 million dollars on the Steam release on the first month.