Sure, asexuals make up a very small percentage of our population, but it's not irrelevant, as it demonstrates that there is more to their lives than just romance and sex.

Only if you suffered a whole different genetic malfunction/mutation then yes. But it doesn't show that the average person can't without complete romantic interaction.

The main point I'm trying to get at is that if you set your standard for life's value to be the one main thing you cannot achieve, then you will obviously feel as though life has no other purpose - which is a terrible mindset to hold.

What's the purpose of life is subjective. The pursuit of women has been one of the major goals for one's life since the beginning of time, along with food, great wealth, ruling of kingdoms. It's not much of a choice either, you subconsciously place that as the highest value of your life and go forth with it. It's naturally going to be the highest value for an incel even more than the average person because you want what is most rare. I have money, relatively decent "power" or social standing in terms of class, food/materials aren't a problem but like the post I linked you above, I don't have the "love" aspect of my life. There's no doubt in ,y mind the average person subconciously places their great value in life in the opposite sex. Be it just interacting women/chasing them, looking for the prince/priness of their lives, their companionship, general validation from them, starting a family (a huge % of the population wants that I'd say), extending their blood lines/family/genes, and then just the plain pleasure of sex. The average person does not pursuit great amounts of food, or powers life a president, perhaps money but in the end they fall into the middle class. I'd say the average man wants these in nor order: a good women, a family, enough money to provide for them/himself. Wonderlust/traveling, a good car, humanitarian efforts are all just small miscellaneous things of ones life. You're right that social interaction is probably the most important aspect in ones life to remain sane but that includes the opposite sex and what comes with them. You're deluding yourself if we're just talking about same sex. If we're missing a part of that "social interaction" then you can see why we're fucked mentally as it is part of the greatest aspect in human life and all of it is important. You don't choose to have this terrible mindset, it is only natural and develops over time.