While there is a natural "that's not fair!" reaction to this, and also I think that a lot of these companies are selling snake oil, I also have to wonder if it can be much worse than the human screening most applicants go through for these kinds of jobs.
A lot of this is probably mostly BS-y stuff like personality tests and so forth. But if there's a stack of 100 resumes applying for some job, there's going to be a lot of arbitrariness in any heuristics used to cull pile down to a reasonable size even once "obviously" unqualified candidates are filtered out (and even that filtering can be a bit arbitrary).
