The problem with 'curing hair loss' is it's not considered a disability. Hair loss is considered a natural part of life for most people as they age, and therefore the industry views it as vanity more so than a condition. That's where the risk lies, because hairloss has no medical necessity it's 1000X harder and more expensive to cure. This is simply due to the fact that because hairloss doesn't negatively (at least medically) impact a persons life, the treatment for it must have 0 potential risks of side effects, because the company that cures hairloss and ends up creating another actual medical problem is going to get sued through the rear-end. Just look at what's happening to Merck with Propecia, all of those class lawsuits because healthy men, who were just losing their hair are now experiencing side effects that don't go away.
Now, if hair loss lead to death, and one of the possibly side effects was erectile dysfunction people are more inclined to accept the side effect. To cure hair loss, you almost need no side effects, and the amount of investment to go through clinical trials only to determine side effects is a huge deterrent to many venture capitalists and private equity firms.
If you're an investor and someone tells you that you can cure life-threatening cancer, but have to go through 400-500M dollars in clinical trials to get FDA approval and a possible side effect is high blood pressure, you can live with that. If someone tells you that you can cure hair loss and a possible side effect is high blood pressure, it's a lot more of a gamble because if people start suffering heart attacks then you put their life at risk for something as minuscule as hair loss (general public perception). It's always ironic that the people criticizing people who do comb overs, and don't want to fully shave their head and live bald are generally the people with full heads of hair, who also will never shave their head.