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.