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?
The most likely to happen is that the current administration starts censoring internet content within the US. The information would be deemed dangerous, or whatever other justification they think would work. The site itself would still exist, we just wouldn’t have legal access to it any longer.