I see it's coming up in 'women in the military' discourse again, the most tedious discourse, which is saying something.
Men are absolutely not wired to protect women out of instinct.
Many chose to be, and they are good men for it, but it is a choice they made, not some innate thing within them.
History bears witness to this over and over and over again. In my own life, I can bear witness to this: imagine a near-seven foot tall man looming over below-female-average-height me, shouting over some supposed professional slight about paperwork (I needed personnel numbers for something I'd gotten saddled with), with several men in the room and they all sit frozen even as I bolted from the room. This happened, and not even when professionally informed by me that this happened and I felt physically threatened did anyone do anything about it. My female friend also witnessed this alongside her male boss- also a large man- and when her boss asked her afterward in befuddlement if he should have done anything, she said, confused and angry he was even asking, "Yes!" And he still did nothing about it. He was not a good man generally, so this is unsurprising.
Hell, a few weeks ago, the discourse was centered upon how men don't owe women any protection- clearly then a voluntary thing, not a core undeniable impulse fundamental to their manhood.
So when you discuss women in the military, keep it to the physical stuff, hell, even keep it to the drama factor (not remotely wholly removed in all-male units, as history and many a tale involving major bodily harm can attest), but if you bring up "women in the military are bad because they cause men to instinctually want to protect them making them neglect their duty", I can safely categorize you as an unserious person who is not worth listening to on this topic.