libertarians, BTC-guys, privacy... these guys are here due to quality, not quantity. 
when they want to reach a broader, normie audience, or sell stuff, they go to Big Tech social networks. 

Another point: nostr does not even have reliable reach measurements. 
if a vendor can not know how many views, clicks, etc, his posts generated, he can not estimate their worth. 
posting is worktime for them, there are not here for the info.  

 True, but I put all crypto in this group, not just bitcoin.  which is a much larger audience
now a lot of them you will likely call "shitcoins" and that's often true.  but they are shitcoins because of them NOT coming on nostr