User blog comment:Big the cat 10/A Veteran Admin’s Concerns Regarding FANDOM and UCP/@comment-40097997-20200825161755/@comment-26939652-20200828080742

(also, 20 years experience in webdevelopment)

Yeah, that's the premise here. That they wrote shit code in the past 10 years. So how are they going to do any better? They still need tons of custom code tacked on top of MediaWiki to support community management features and you can already see that they're having trouble with it - many features that are needed haven't even been implemented.

Doing these kinds of migrations you need to identify the features that are vital to exist before migrating. And they haven't. This is the primary reason for the enormous backlash.

Yes, in general people are resistant to change, but that's not the bulk of the complaints.