"he could easily build a much better rival with different values."

Steretypically of social media - I see Twitters greatest asset being it's current network of influencers, analysts, thinkers, artists and colleagues. All the people I want to follow are already on twitter. I don't care about the platform or the tech, I care about all of the interesting people posting there. I would claim that is the true power of the platform atm - it's network.