By default, most of us host the people we follow and the people they follow (friends of friends), so when you're following a pub you're hosting all of the people that they follow, which could be anyone. For me, it's a question of whether you want to host content from people who have pub invites or whether you want one of your [human] friends to follow them before you want to host them.
Lots of my friends follow pubs and follow new users, so even though I don't follow pubs I'll still see lots of new folks, but personally I've found that the firehose of brand new users is a bit of a drain on my attention and sense of community. On the other hand, I started out as a rando with absolutely no scuttle-friends, so I appreciate that a real person (@fabian!) followed me, which would have introduced me to folks who don't follow pubs.