Embrace Extend Extinguish
Everyone knows large companies wish to extend their power to every part of our lives. Who remembers when Facebook purchased Whatsapp or AT&T purchasing Time Warner? There are better examples but I think you understand where I'm coming from.
The Linux Example.
Many linux users express concern that large company partners of the linux foundation may be involved in these tactics. Looking at the corporate members page reveals some disturbing names. why might Google, Microsoft and Facebook want to sponsor Linux? Google owns ChromeOS which is built upon linux with Google closed-source code of course. Microsoft has Windows Subsystem for Linux (WSL) which allows some linux applications to be directly run in Windows 10. Facebook tried and failed to make a Facebook phone platform a few years ago and owns Oculus VR which uses Android as it's operating system.
The Mastodon Example
According to this article from December of 2019, Twitter will be hiring a team of 5 people to either improve upon or create a new standard for decentralized social media. Sound familiar? Twitter knows that in the long term the fediverse is a better solution. They will attempt to come in, corrupt ActivityPub, and then kill other fediverse projects who don't want a corrupted standard.
Thankfully, this will not be an easy task. A lot of Mastodon users fled Twitter for their own reasons. They are not likely to go back under the thumb of Twitter without a major fight.
Many mastodon instances would block these Twitter instances. This would effectively isolate Twitter users into an echo chamber until they were ready to leave and join the real fediverse.