What possible reason a H visa won't pass?

[cindywang16]

I heard a company said they often applied H for their employees and for some reason several of them didn't pass.
I don't know what could be the reason.
Could anyone give some example?
What could case a H application did not pass? since the company always filed for their employees....


thank you,

 

[GotPR?]

Company is not paying prevailing wage.
Beneficiaries do not have degree or experience for H1 job duty.
Job duty is too geneal.
They filed when quota is not available.