You generally don't have to ask a person if they're deaf. Unless you mean it was part of the application/submission process? It sounds like a greatly exaggerated version of the truth, which is this:

The actual requirement for government contractors is that they cannot require someone to disclose disability information, but they must give the applicant the opportunity to do so.

Because roughly 10% of the workforce has a disability, and it was found that government contractors appeared to discriminate against people with disabilities that were otherwise qualified for the work. So, large contractors became obligated to have a less-than-representative 7% of their workforce pulled from a pool of candidates with disabilities.

I'm not sure quota systems like this are the best way to handle the problem. However, this approach is hardly the death knell for merit-based hiring.