> [..] you don't get to decide what "social good" is
Well, technically I have a say, I elect my leaders and can write to them with my opinion. Often it is the case that salesmen and charletons get into those positions but the basic premise of those positions is that they're intended to act in the social good. What you propose is that somehow tech companies will act in the social good by themselves, which I find particularly dubious.
All capitalist companies (and by that I mean, any company that is enjoying success in a capitalist society) have an often unstated goal of monopolising their market.
It is a natural outcome of competition that eventually there is a victor. The whole premise of capitalism is that competition is good, but eventually the strongest will win and you have a monopolistic leader.
The only antidote to this is regulations.
Making the argument that regulation hurts smaller companies is also something uniquely American. This regulation (and many other tech regulations) are really aimed at people abusing their position today, not some theoretical startup that somehow captures 60% of a market overnight.
FWIW, I actually really like iMessage and agree with the decision Apple made not to open it, but I can't abide talk like this because a lot of people seem to think that regulation is somehow anti-capitalist, when in reality regulation is the only thing that could keep the capitalist machine running once there is a monopoly position or a sufficient moat around a service.