You say that like it's a bad thing.

Can you imagine a more effective way to incentivise more people to start even more disrupting platforms? Can you image a more effective way to get investors to give money to these upstarts?

It's much easier to get your rabble-rousing startup to threaten disruption (and then be bought up as a precaution), than if you had to actually battle it out in the marketplace to the bitter end.