From a simple game theory perspective there's no way any individual generating steady income or retaining a large portion of the steem created would ever want to accidentally invite any users to the platform who would prove themselves to be capable of both reducing the geographical vulnerability of the network and improving the network by creating useful services that run on the blockchain. Competition is bad, mmmkay. But as an aggregate they would be better off trying to improve things because the market will eventually punish us for our hubris when other social media websites come to steal our ste... thunder.