Because they thought it was too ‘woke’ and wanted to burn the books.
FWIW you can download it: https://en.wikipedia.org/wiki/Wikipedia:Database_download
Edit: Lots of good answers. When I ask the question I mean the main site. We would all have access to it. Hell I downloaded the text yesterday on two computers. I mean could the masses ever be denied access to wikipedia in the only form they are used to?
Yes they could in several ways but not without causing massive upraw.
They could put financial pressure on Wikipedia by making payment processors stop working with them like they did with Wikileaks.
They could get ICANN to pull their domain. (I doubt ICANN will do it though)
They could tell ISPs to stop resolving Wikipedia’s domains on their name servers.
Authoritarians don’t care about what the hoi polloi think.