That article is one in a series. Perhaps I was wrong and it is not clear or well-argued without the context of the broader series to draw from. It's a shame because it is actually painstaking in its argumentation and attention to nuance, and by far the most insightful series of its kind that I've ever read.
When you say "chances are you are a bigot" you may technically be correct in the sense that from a random population of "I'm not a racist but" statements, more than 50% of them are said by bigots (in fact, I would probably estimate this much higher, as bigots say it more frequently, in my experience). As for my-literal-self, and almost everyone who is reading these comments (well educated, left-leaning startup enthusiasts), I have significant other evidence that I have to weigh against that proposition (i.e. my recollection of my lifetime's past events and explicit knowledge of my views and beliefs), so if I were ever inclined to use such a phrase I wouldn't actually be making a bigoted statement. Unfortunately, some people who are less thoughtful and less capable of a nuanced understanding of argumentation would immediately turn off their brains and assume whatever this counterfactual self said next was bigoted. People like that have bad rhetorical hygiene and arguing with them should be avoided if you don't want to contract memetically transmitted diseases.
Saying that bingo cards are a "useful tool" is doing a disservice to the word tool. They are, if not actively harmful, merely a form of entertainment, and no more a tool than Star Trek VI.
> "it is actually painstaking in its argumentation and attention to nuance"
No it's not. It doesn't follow anything through to a conclusion, it just berates people who attack strawmen, or who dismiss others' arguments out of hand, whether that dismissal is warranted or not.
Just taking the "I'm not racist but.." argument on that post: are you really saying that there is no other way to phrase your argument? It's guaranteed to cause a reaction in everybody with an opinion on the issue and it's somehow their fault for not giving your argument proper attention or missing a nuance somewhere?
And then you complain about bad rhetorical hygiene. State your case in a way that your audience can understand and engage with it, and you'll get a better response.
What conclusion were you looking for exactly? It was an empirical recounting of events, peppered with an analysis of why the events are so frustrating for the author. Did you expect The Essay That Ends Racism?