very true.. maybe offer an option to newcomers to create a "one time" introduction post that will either have it's own feed
OR
include a symbol of some sort.. like the symbol shows for choosing 100% steem power, when you make a post.
that way.. in the #introduceyourself hashtag... you can easily identify the newcomers from everyone else
Or: just show some commonsense and some manners and don't tag-abuse :P
if the content is obviously nothing to do with introduction of some sort.. yea, don't abuse.. I agree with that.
I've also used #introduceyourself to introduce other "characters" I play in my films and skits.