Do you want another example: Intense Debate.
https://wordpress.org/plugins/intensedebate/

Technically, the best feature-packed plugin to drastically improve commenting experience on wordpress blogs.

Integrated into Automattic.

And totally abandoned.
The support threads full of people reporting huge issues that have never been fixed.
I myself gave up on it after seeing it became SQL error hell in my server's error logs because of the plugin with recent wordpresses.
The plugin code never adapted to mobile device users.
No contact option anymore, just a vague FAQ.

I'm not saying Automattic is a bad company, far from it, but as all companies, they're bound to lack in some regards.

Well, plugins are one of those areas, they abandon some plugins and forget these plugins' potential, forcing users to migrate, this is a pity :(

So, hey, dear Automattic people, check IntenseDebate, it would deserve a revival :)