Zero-rating your own services is something entirely different than zero-rating services of other companies though.

It is no different than a car manufacturer paying for their own highway lanes. If half of the highway lanes are BMW-only, would you still buy any other car? Free market resolve this by competition based on price, but if I wanted to start my own car manufacturing company, I wouldn't be able to compete because a smaller player in the car market wouldn't have enough funds to get the various levels of government to implement MyNewCarBrand Inc. Roads (TM)