How the patent system crushes innovation

David Graeber quoted Neal Stephenson on how patents actually hinder innovation instead of encouraging it:

Most people who work in corporations or academia have witnessed something like the following: A number of engineers are sitting together in a room, bouncing ideas off each other. Out of the discussion emerges a new concept that seems promising. Then some laptop-wielding person in the corner, having performed a quick Google search, announces that this "new" idea is, in fact, an old one—or at least vaguely similar—and has already been tried. Either it failed, or it succeeded. If it failed, then no manager who wants to keep his or her job will approve spending money trying to revive it. If it succeeded, then it's patented and entry to the market is presumed to be unattainable, since the first people who thought of it will have "first-mover advantage" and will have created "barriers to entry." The number of seemingly promising ideas that have been crushed in this way must number in the millions.