> Eg. it may be more lucrative for drug companies to research hair-loss or acne drugs than something like cholera.

This doesn't seem especially unreasonable; hair loss and acne, to the extent they are problems, are unsolved problems. Nobody disputes that cholera is a problem, but it is very much a solved problem.

Cholera is mostly a solved problem, but the point stands in relation to other diseases. There's much more interest from Pharma in hair-loss, acne, Viagra competitors, and in $1,000,000-per-treatment cancer drugs than in mundane but vital tasks like finding better treatments for mental illness, finding better treatments for migraine headaches, or finding new antibiotics before our entire current spectrum of antibiotics stops being effective.

Pharma spend a lot of money on mental illness drugs, because rich people will pay for them, just like hair-loss and acne.

I completely agree with you that this causes a misallocation of resources, but mental health is probably not the best example you could have chosen.