We can't observe gods, but women exist empirically, and men have had to live with them all along.

Rather then mocking his phrasing maybe you should try actually paying attention to his point.

I was doing both. And nobody has yet pointed to a valid reason why, just by the mere presence, truth should ooze out of things directly into our minds.

The process of intentionally acquiring truth is costly and fragile: you need to experiment, be willing to discard ideas, formulate wildly new theories.
If the truth is not immediately strategic, i.e. it offers no immediate and perceptible disadvantage, it has no particular selective pressure against in a clash between cultures or different memetic spaces. The truth can even hinders the success of a tribe, acting through our biased brains.

A ship disappearing behind the horizon, fire, women are all observable phoenomena, and yet we had (have) flat earth, flogiston and discrimination.