I think the reason comes from something similar to the article. Smarter people don't "need" perfectly pristine aesthetic code because they have the brain power to easily read messier code. It's not universal. Some smart people are obsessed with neatness but because neatness just isn't required you see this correlation with sloppier code and smarter people.
I have found that it is nearly universal that stupider people need to obsess over neat code because they literally have to have it or things get too hard for them.
Also yes, it's not universal but I have also noticed less smart programmers tend to like golang. There is definitely a correlation.
I know this can come off as a bit offensive for people who like golang or really obsess over neat code. I just want to say my statements are general, anecdotal and I have definitely seen examples to the contrary so I may not be referring to you personally! I'm referring to a general tendency I see.