Like most editors on Wikipedia I too added a few categories to an article just to keep the bots at bay, as they were never really of much use.
Not sure why this basic fact escapes the great man, him being regularly feted as a great builder of the wiki, but nothing is guaranteed to ensure the Wikipedia category system is of much use more than if established editors just slapped a couple of categories on to keep the bots at bay.
Eric never was a supporter of those Wikipedians whose interests lay more in the maintenance and curation side of things. Indeed, that is being generous, open contempt is more like it. One job those people do of course, is to go through the bot identified lists of uncategorized articles, and do a proper job of it.
I like to think this was what was meant when it was famously said Eric is not a Wikipedian. Sadly, they only meant because of how much of an asshole he is. Which tbf, applied just as well. Being an effective Wikipedian is so much more than the unremarkable ability to write an article.
So here we are today. We can only guess how many articles he wrote or rewrote, which to this day, have perfunctory categorisation. Only now have I just realised that proper categorisation isn't even part of the GA criteria. So that explains why he felt comfortable doing GA assessments without any apparent knowledge of or will to categorise articles properly.