Because those big businesses are only motivated by the profit possibilities.
If you take away that protection then they'll just stop trying. They don't give a shit about any of the motivations you listed. They'll wait for you to come up with something new, then use the advantage of their size to force you out of the market. You'll end up either giving up or trying again at which point they'll just repeat the cycle.
And there's nothing you can do to stop them because now they can be as open and blatant as they want with directly using your exact plans.