> For Twitter, developers prevented monetization.

Except that they didn't. There wasn't even any discussion, it was just "We're capping OAuth tokens.". Developers offered to pay for access, users offered to pay for the ability to use 3rd party apps.

If they didn't want to go down that path then Twitter could've easily required developers to show monetised tweets/ads.

Just because Twitter couldn't figure out how to monetize their APIs? Please. They could have made some premium before. They could have forced ads in the tweet stream as part of the usage requirements for the APIs etc.

They killed a community due to arrogance. And it backfired big.

It was early on to come up with any conclusions but dropping developers in the XXI century? Do you know any other company who did that?

The problem with Twitter was more serious: they never gave a concise and frictionless way to pay for the API. For example, Google innovation with AdWords was providing a self and quick service to put ads while other providers like Yahoo required a process with a lot of friction. Twitter logic was prehistoric.

They haven't monetized even after kicking off the devs. :)

"prevented" only in a narrow way if you ignore the long-term benefits that developers would collectively bring.