...they presume that's all we think about because they project teleiophile tendencies and neuroses about sexuality upon us. They refuse to see us as multi-faceted human beings, but only obsessively focus upon the sexual component of the overall attraction base because it's the only part of us they want to see and focus on. They are, as you noted, far more obsessed with sex than the average MAP could ever be. Because they cannot see kids as full human beings, they presume that we can only see them as "objects." In other words, the project all of their own shortcomings onto us.

They also function from the common neurotic anti-sex attitude that if someone has sexual desire as part of their overall attraction base, that means it must be the only thing they want. I'm sure many happy adult couples would find that rather bizarre.

They see sexuality as a corruptive taint on love, the latter of which they view as entirely pure and bereft of its own dark potential, including the tendency to cause people to try and control and even hate the people they care about in some sense (since hate is merely the flip side of love, not the opposite; the opposite of love is actually indifference).