Also, when Twitter yoinked API access from 3rd party developers, that convinced VCs that continuing a bait-and-switch with APIs was lucrative.
That they could fund the next potential monopoly.
The result was competing walled gardens -- and that has hindered the Internet's development, perhaps set it back for decades.
People often forget that a core selling point of Web 2.0 was interoperability.
Yay! You could embed! You could build plug-ins and themes!
But so much of it was a mirage because too much of Web 2.0 was built off corporate-owned APIs instead of open protocols.