Twitter? No good way to monetize. Groupon? Failed to monetize effectively after virality faded and without a moat competitors did the same thing. Yelp? A web version of the BBB protection scheme whose profit comes from the shake down protection racket against small businesses, not from users. Zynga had no moat and other companies quickly did the same thing with much leaner overhead, like King and a dozen other cheap but profitable game makers. Box was just overvalued for what it is.
On the flip side, every time someone takes an Uber or rents a room on AirBnb, they pay the company.
As in, those companies accept money for every transaction and profit on them.
Twitter, box, groupon, yelp don't do that. And Dropbox doesn't and they aren't publicly traded and if they did sell stock it would probably be overvalued and shrink over time like Box.