Because it is a waste of time, money, and perhaps most importantly: Research.
Some of this sh*t in the pipeline has little to no scientific support to suggest it will work or in some cases, evidence that it won't.
The biggest of course being JAK Inhibitors. Yeah, theywork well for AA, but we've already seen that patients who also have Androgenetic Alopecia don't recover from that along with it. Neil Walker's excuse is that a topical will be able to reach the follicle, but as Swoop pointed out and cited studies on here numerous times, that claim is pure bullshit. Drugs have no problem reaching the outer layers of the skin; including JAK inhibs.
Also, not one person can put forth a sound theoretical basis for why JAKs would work for Androgenetic Alopecia. Every time you ask, you just get hit with a ton of personal attacks and dodging the question. Nasa_rs, the biggest JAK fan on the web's reasoning for why he thinks it will be the cure is, and I'm not kidding "Works for AA, might as well work for Androgenetic Alopecia" because that's totally how it works lol.
So it's a near guarantee that Aclaris' trials for it on Androgenetic Alopecia will fail miserably. But here they are, pouring funding, time and manpower into something that could've gone to something else that actually is worth it.
Tsuji, Follica, Replicel, I guess this Choi dude, and others like them are, over about 100 years, the only types of methods that have proved themselves to be relevant, promising therapies for treating Androgenetic Alopecia and we'd all be better off if more companies invesitaged similar methods.