I found an estimation that only 2% of the population has an IQ that would qualify them for MENSA (130+)
en.wikipedia.org/wiki/High_IQ_society
Of course, we do not argue that genius IQ is not selected-for or that it does not increase fitness because of the rate at which we find the trait n a population.
Genetically-linked traits that are consistent and promote fitness are selected-for. The gene that causes sickle-cell anemia is highly selected-for. But only in certain environments. In those environments, it increases fitness. This isn’t simple science, like chemistry, evolutionary science is the most complex branch of science there is.
The concept of “altruism” in evolutionary biology explains a lot of traits, behaviors and systems that would seem, at first glance, to be contra-survival. **Same sex attraction can be considered one of those altruistic traits. **
Individuals do not evolve, populations do, and so, the trait, the gene, the behaviors all have to be considered in terms of the population and the forces that drive changes in overall genetic frequencies.
There is no “wrong/right” dichotomy in evolutionary biology or any other natural system or process. There are behaviors that can increase or decrease fitness and survivability.