Cost, experimental drug, shady source, verdict not officially out on efficacy... I mean there are a lot of reasons, lad.
And how about long term safety? Shockingly, some may not want to drug themselves indefinitely, especially considering the above factors.
But I mean who knows? To each his own, etc.
I am of the unpopular opinion that it seems easier to shave it off and invest time in making that work - finding friends who don't give a sh*t about hair, tricking a girl or two into falling in love with you (like many bald men have evidently done), having a fulfilling career, maintaining health so you have that peace of mind and quality of life, and being an intellectual, open person - rather than fight with my body, f*** around with unknown substances, have a high likelihood of my hair going to sh*t anyway, and basically riding this hairloss rollercoaster for the next decade. That sounds like a fuckton more work than shaving it off, taking a year or so to just get over my appearance and redoing my wardrobe and maybe finding some other sh*t to spend my life on...
The caveat to that is that if you subscribe to hlc2020's line of thought, the cure should be "right around the corner" and so presumably the maintainence drugs would simply tide you over till then. Who knows?
For me, it is Replicel/Follica/KY Choi/Tsuji or bust. In approximately that order. I don't really want to deal with systemic drug use. I'll just take the hit to attractiveness
I'm getting older every day... my health will only tend to decline. Down the line, my body will tire and I'll care more about cancer and heart disease. I'd rather avoid systemic drug use given those concerns.