I've been at more than one company that migrated _from_ MediaWiki to Confluence. It usually boils down to "non-developers have to use this and Markdown+plugins is hard".
Turns out no matter how much better the thing is, the users have to know what they're doing more than the operators do.
Turns out no matter how much better the thing is, the users have to know what they're doing more than the operators do.