You need only google the phrase "eye contact hard" to discover that what you say is
not universally true.
But I think you're tapping into something deeper, something I was going to respond to in my original comment, but thought better of it because you [edit: they] hadn't actually made the argument at that point. Now you've flirted much more closely with it, so I will say it:
There is a modern suspicion of the entire concept of teaching men how to raise their sexual value. There is a sense that it involves "faking it" somehow, or that it represents an unhealthy obsession, or means the man is only interested in sex. But it's this taboo which permits the distasteful 'PUA' community to flourish - it pushes the practice of self-conscious improvement to the fringes, where taboos are disregarded. It's a dangerous state of affairs when a man's best hope at improving their lot is toxic misogyny. Far better if there's easy access to good, practical advice that works, alongside a healthy worldview.
It's notable that the taboo is only for men - we don't assume a woman "probably just wants to have sex", just because she puts on lipstick (the purpose of which is to simulate attraction!)
(It would be interesting to further explore the sexual politics behind this taboo, and why the corresponding one for women is so much weaker, despite male noises about "preferring girls who don't wear makeup", and in particular how such taboos are powerful weapons in the 'battle of the sexes' that improve the ability to distinguish fitness levels in the opposite sex - but it's a fairly hot can of worms that I'd rather just allude to than attempt to untangle here.)