The company is hoping that no one would apply for the position that they have posted, and if someone does, they will find a way to declare him/her unqualified.
These ads are part of the "labor certification" process to obtain an #H1B visa (work visa) for a foreign worker that they have already decided to hire for the position .
U.S. immigration authorities require companies to place such ads and demonstrate that the company "could not find a U.S. worker who could do the job", and therefore justify the need to hire a foreign worker for the position.
That is why the company hopes that nobody would apply and if someone does, the find a reason to disqualify him/her.
This is an abuse that is rampant in tech industry. They bring in cheap foreign workers to the U.S to replace U.S. workers.