I imagine part of the problem is many of these coding schools are scams. It isn't that people can't learn from them, but what they are teaching is usually just too narrow to be all that useful.
How is it a scam? It's a month-to-month subscription service, $25/mo. from what I recall. They didn't charge 5-figure tuition and offer weak "job guarantees", which is what coding bootcamps do.
They stole much of their initial content from other people and ripped all attribution from it. I found two of my blog posts on their site, without any attribution or permission.