It would still be a gradient even if the distribution of where people fit into it isn't even. The way my sociologist professor explained it in school was that the gradient is for "attraction" and like some appreciate the attractive qualities of one gender while not actually having any desires attached to that appreciation.
But doesn't that commit the same fallacy of trying to fit your data to a specific model such as a "gradient" view rather than a binary view, when in fact it fits neither , both of these views are "essentialist" in that sense. Besides there's certainly a different between an aesthetic appreciation and a sexual desire, someone might have an aesthetic appreciation for a car or mobile phone for example.
Sure, you could think of it as one gradient (gender) mapped to another (sexual orientation). The whole desire of us to classify these things into neat little labels falls apart though when you look at research and ethnographies of different cultures that did things differently.
Most societies I am aware of still have males and females. There are various exceptions - e.g. various groups that perceived to be "outside" of the binary structure - but these would be still defined groups and there still would be labels. Could you give examples - more than one - of cultures that really perceived gender as a gradient?
For sexuality it is more complex since not all cultures have western fixation on sexuality and thus the question of who rubs which part of their body on which part of whose other body may not be as prominent as in our culture. I.e. they may have a concept of "gay" but it would be as big part of one's identity as "coffee drinker" or "likes to wear jeans" is in ours.
But does a gradient really provide a clear picture if ~90% of your data points stick to one side or the other? To me this seems to be just as clumsy as a gay straight/gay/bi classification system. Either way risks warping your thinking as described in the article.
We are talking about people. So I think this kind of research and distinction makes for a powerful reminder of why tolerance for diversity is so important. Were those young people who do not happen to fit so nicely into these categories encouraged to be themselves rather than conform with 90% of the other data points, maybe they could live happier, stress free lives.
Or your sociologist professor is wrong, and the majority of the human population only orients to one sexual attraction or the other in binary, which makes a lot more sense from an evolutionary point of view.
