I think that some of that comes down to the fact nostr was conceived and is mainly being developed by people from the bitcoin community. And as a result, the largest group of people on nostr are bitcoiners. Doesn't help that many "normies" think that bitcoin=scam, so when those same "normies" join nostr some of the first things they see are about bitcoin so they nope the fuck out. It ends up being a chicken-and-egg problem caused by the fox having a field day in the henhouse. I think that if bitcoin haters can be convinced to not just join, but ignore bitcoin content altogether, we can get the diversification of content people want. 

 too much bitcoin  noise for nocoiner who dnot need any coin infact - technical stuff is all good - but  experts fro other fields have not arrived yet. possible due to 90% btc heavy crowd