The point of Tok (as I understand it, oversimplifying it), is that the masternodes get "free" coins for their service, contrary to the miners need that they need to pay it with electricity bills. That is the "pressure" force.

The collateral of masternodes are also a "working" mechanism in this ecuation. This 70.000$ can be located anywere else. The more reward, the more masternodes, the more collateral locked.

And always remember the main point for me (economics aside): We don't need the 45% PoW force anymore. We as a blockchain we don't need to waste the energy for it.
And that's something important for me, and I'm sure for more people out there.