Why is it some companies advertise like mad about their JOBS--enough for several salaries, yet they won't hire

Answer 1

A lot of companies do that, it is called: applicant pooling. My Co. does it all the time.

Answer 2

sometimes they just want to make sure they have lots of applicants so they can be picky about who they actually hire.

sometimes they are just trying to prove that they are recruiting a diverse population but they still go ahead and hire who they want.