One reason is that plenty of powerful people default to zero-sum thinking. If there's money involved, they would like most of it to be theirs. Long ago I read something from Philip Greenspun where he talked about Oracle's pricing strategy, and it went something like, "Take all of your money, and then another $50k/year for support."
Which reminds me of a quote from Brian Cantrill: "You need to think of Larry Ellison the way you think of a lawnmower. You don't anthropomorphize your lawnmower, the lawnmower just mows the lawn, you stick your hand in there and it'll chop it off, the end. You don't think 'oh, the lawnmower hates me' -- lawnmower doesn't give a shit about you, lawnmower can't hate you. Don't anthropomorphize the lawnmower. Don't fall into that trap about Oracle." -- https://news.ycombinator.com/item?id=5170246
Which reminds me of a quote from Brian Cantrill: "You need to think of Larry Ellison the way you think of a lawnmower. You don't anthropomorphize your lawnmower, the lawnmower just mows the lawn, you stick your hand in there and it'll chop it off, the end. You don't think 'oh, the lawnmower hates me' -- lawnmower doesn't give a shit about you, lawnmower can't hate you. Don't anthropomorphize the lawnmower. Don't fall into that trap about Oracle." -- https://news.ycombinator.com/item?id=5170246