From the article:

> She wasn't saying, of course, that it's impossible to become a billionaire. Obviously that's possible. Nor was she talking about the distinction between income and capital gains. She wasn't making a point about accounting. What she meant was that it's impossible to get that rich without doing something bad — without cheating in some way.

IMO, that's a pretty fair interpretation, given Warren's rhetorical history.

> ...one doesn't earn a billion dollars through work alone > set up a structure that extracts a billion dollars from a market

If we accept that interpretation (which I don't), in what way is the latter not "work"?