There was a time about 5 years ago where tech companies were desperate to fill various minority quotas. The idea was those people were very valuable, there were very few applicants who were hotly contested by other tech companies, and lack of skills wouldn't matter - they'd learn on the job.

In that world, the school only has to get the students to do a "hello world" in python and apply for the right jobs. Such a school is very cheap to run, and very lucrative as long as a decent proportion of students fit into the desirable categories.

The students themselves usually aren't aware how desirable their application is - and therefore believe the school is their route in rather than a few youtube tutorials and a direct application.