It follows a feminist narrative where woman are asexual beings and sex is something only men like and force upon women. (sex-negative feminism) In such a narrative every statement of attractiveness is ultimately a outing a want-to-be rapist or a predator. If you are in such a narrative it also makes perfect sense to say it's sexist. Outside of that narrative hardly.
So, looking at somebody consensually is "eye sex" and non-consensually is "eye rape"? I have to say... I can't take this vocabulary serious.
/edit
Looking a somebody and having sex with sombody is as far apart for me as a hand shake and a MMA fight: the polar opposite sides in the spectrum of social interaction.
Nope, just that if what you want is consent, and if you don't permit consent to count unless it's genuinely meant - no pressure, no arm twisting, no punishment for a "no" - then it's damn hard to contrive a circumstance where in a patriarchal society, a man can assume a woman is consenting. "Yes" can only be understood as "yes, given the estimated probability of consequences for no". And it takes a whole lot of effort even to blunt that a little.
It's absolutely not meaningless. The opposite! But it's hard.
And yeah, that means for most people who aren't putting in the unusual effort, most nominally mutual intercourse is somewhere from slightly to heavily contaminated, depending on things like "how abusive is the relationship?". Call that what you will.