Piper Chapman is described as the protagonist in the show in every summary, description, and article detailing it. The only other character that is occasionally referred to as the secondary protagonist is the black female character "Taystee" who is straight. None of them ever refer to Suzanne as the protagonist as the show. Important character, sure, but not a protagonist. But, please do tell me how you know something that all of the professional analyst, critics, or even the creator who based the name of the protagonist off the woman who wrote the memoir from which the series is derived don't.
It's quite simple math. Within the last two years we've had at least two major film pieces, one movie(moon light) and one set to appear on hbo(issa rae's show) with lgbt black male protagonist, and unless you're telling me we had over 97 other straight black male protagonist in major film piece in this country within the same time period, then they are indeed over represented in film in comparison to their %2 share of the actual population. If you have an issue with basic math, then I don't know what to tell