Yes, but evolution is stupid, so our sexual instincts are not very well-aimed. Rather, like much else of cognition, they are a bunch of hacks thrown together, which then require arbitrary patches like a cuteness response to solve problems like parental care

There is not necessarily a contradiction between asserting that an instinct is "well aimed" and observing that it is a "bunch of hacks thrown together." Because phrases like "well aimed" are really a kind of shorthand for talking about effects not intent. Thus, nobody would claim that a "selfish gene" really has feelings of selfishness.

which then require arbitrary patches like a cuteness response to solve problems like parental care.

Sure, and if the combination of instincts work reasonably well together, it's not necessarily a problem that the cuteness reaction reacts stronger to bunny rabbits.