Well, I've never heard that transplants are twice that, but the average white male doesn't have "8-10" times that many hairs; average hairs per square centimeter for males is 124-200 (
https://www.ncbi.nlm.nih.gov/pubmed/10417585) - a significant variation in density, with fair-skinned, fair-haired people have less density, and darker haired, darker-skinned having more. So, if you're naturally on the low end of that range, 25 hairs per square centimeter would represent a 20%+ of your prepubescent baseline. Further, that's NEW hair, not hair taken from some other place on your scalp and implanted, which is all a transplant is. For a white male with light-colored hair and a lower Norwood (<NW3), that takes you back to a NW0-1. There is nothing currently available that comes close to producing that sort of de novo growth, and for low NWs like me, it's essential a "cure," albeit probably one that will need regular maintenance via follow-on treatments and continued use of anti-androgens.
This exactly, but I would caution that we don't know if its repeatable; for now, they are claiming 25 new hairs per square cm, and haven't publicly stated - as far as I know - that additional treatments result in additional growth.
It has nothing to do with "gutfeeling." Follica has only stated publicly that they can achieve 25 hairs per square cm; if the protocol's results were compoundable, they'd probably have said so. Additionally, other research suggests that reinvigorating newly miniaturized hair is more difficult than waking up long dormant hair, so those who are high NWs that have been slick bald for a long time are going to have a harder time growing new hair. So it does make sense - given current data - that higher NWs are harder to recover than lower ones, and the areas that went first (hairlines, temples, crowns, etc.) are least likely to return (this is why it's critical to get on the Big Three the moment you notice loss - every saved follicle counts). Can Follica improve their technique? Who knows, but they certainly intend on trying, as they are going to continue to research novel compounds that may result in greater density. But clearly there is a limitation to the wound response, and that it will take further research to fully exploit it (if it can be further exploited at all).