Yes, I work at Refinery29 (obligatory www.corporate.r29.com/careers/), a large women's fashion website in NYC. Of our 30 person tech team, we have had about 5 people coming out of these bootcamps, and they are all awesome. Although I think your idea of who goes to these bootcamps is pretty off. These aren't people who "had never opened a text editor in their lives." Some of them are people who were working in science…
Hm. So since companies do hire from dev bootcamps, are the candidates quizzed about CS theory during the application process? It seems pretty standard to be asked about data structures and algorithms for engineering positions and I can't imagine someone attending these bootcamps to also be well-versed at those over the course of their quick training.
The problem is that people don't practice them because they believe that these questions test some sort of intrinsic, unchangeable quality of how smart you are, which is totally false.
But if people practiced them more, they would realized that there is only 10-20 questions that you can be asked, and everything else is just some minor variation of the most common questions, and you don't specialized training to do project Euler or glassdoor.com questions.