Yea I have noticed that a lot of the users with a higher reputation use the tag for things like cryptocurrencies.
I'd imagine it would be a rather easy and significant fix from the developers end for steemit to implement a block of creating a post in the #introduceyourself tag fro anyone above a certain reputation score. What that score is I don't really have a good idea. Maybe about 30 rep?
Thank you for selecting me to be one of your 5!