[Torie]

since the alternative of a 'polyvalent' continuum is even more contrary to the modern Western culture

I am not sure I agree with that. I also think Western culture is rather good over time in going with the empirical evidence, and I think over time it will be demonstrated that sexual preference among humans is in fact over a continuum, rather than everybody being hard wired one way or the other.

[AntiGuv]

In my view, the greatest impediment toward Western society abandoning the conceptual dichotomy of sexual orientation arises from the modern perceptual association of male homoeroticism with effeminacy. If there is one singular constant found throughout all of recorded history and across every known culture, it is that men in general will go to extraordinary measures to conform with the prevailing norms of masculinity, and that they will mentally or publicly deviate from those only under extraordinary circumstances.

At least in my assessment, this is the ultimate foundation of every cultural order, with all else predicated upon and extending from that.