Ironically, you are doing just that. By your logic, since we are all medically deaf, we must all be similar. If that is your only constraint, you are perpetuating a very old lie about what deafness is.
If you were more forthcoming with what you intend to argue using this data or what the specific focus of your research is, it might be easier to understand your reason for choosing such a broad sample. But all you've said is that you are studying "the communication between the hearing and Deaf communities." As if this is a clearly defined topic. Perhaps one reason you haven't been able to find many participants in real life is because people are wise to your lack of disclosure.
You think I'm just being some asshole, but I have good reason to be wary. Because here is the REAL constant that all deaf people share regardless of what country we inhabit: we all must live in societies where the majority of the population does not understand us but still attempts to define who we are and what is best of us. You seem to be proving that point, yet again.