Imagine a world where everyone used a protocol to communicate. Lets call that protocol "English". Now, imagine "English" is owned by one company, who changes "English" and compromises your conversations consistently, and then tries to monetize your conversations in increasingly subtle and annoying ways.

Now in reality no one owns English. Its an open form of communication that anyone can use, anywhere. You can even create variants of it and use it with your friends as long as they understand your dialect.

"Social Infrastructure" would require a common social protocol as a specification. This would open up an entire ecosystem of smaller players to contribute to it, providing delicious synergy and innovation along the way. Kind of like modding Minecraft, etc.

Not every company wants to become a billion dollar start up. There are many IT service providers and MSPs that are perfectly comfortable servicing 30 clients and making a lifestyle business for everyone involved. If its a commodity, it opens up locality and niche markets easier than a monolithic implementation.

Nothing but good would come from a true technological social protocol. Right now online social behavior is dictated through the mind of one man, which isn't really social at all.

The user value is in that the users have all the power. If social service providers are a commodity, if they misbehave or provide a bad user experience they could simply take their social graph somewhere else. This empowers the user. This is also why Facebook does everything in its power to retain hegemony.