The scammers and hackers definitely top my list. This group has significantly delayed mass adoption and add fuel to those governments who want to heavily restrict or ban crypto altogether.
Also, those people who want to be in the crypto space for the profit but don’t want to learn about it so they expect you to do all the work for them. After being in crypto for almost four years now I realize why more people aren’t financially independent, must don’t want to do the work.