Alright, here is a quick brainstorm right off the top of my head without even thinking too much:

So many apps created then abandoned

User experience in general is horrible

Public private key confusion

Retarded douche bags fighting with sincere people

Gay porn popping up out of nowhere

Lots of spam

Connecting wallets is not easy

Bad relay management allowing spam, porn, etc.

Diminishing numbers of users

New people are used to algorithms, lack of algorithm provides less interest and energy.

Lack of funding for legit apps that we need like a YouTube alternative, Instagram alternative, etc.

Lack of interest by the masses for real freedom and sovereignty

Many new folks see too much Bitcoin posts and are turned off.