If the hiring process is transparent, wouldn't job seekers just figure out how to game it? Unless the process is confidential, and only comes out in lawsuits, and isn't disclosed to the public, this would only serve to further obscure the candidates who can do the job as opposed to just get hired.
They aren't really trying to hide it, they send you an email with a page or two full of topics and links to help you prepare for the interview. The current state where people practice for their interview is exactly what they want.
Yes. But that's already the case and is usually a useful screening criteria anyway. i.e. I don't actually care if you smoke pot or not. But I care whether or not you are smart enough to lie about it during an interview or job screening process, and if you can quit long enough to pass a drug test. Because that's relevant.
If you are intelligent enough to game the system into looking like you meet all of my criteria, you can probably also "game the system" into actually meeting my criteria on the job too.