@f23362a3 @9a3d0e66 yeah, I didn't get this until recently either, but this is the best way to gather interesting content into your feed. If you rely entirely on following people, you won't see as much interesting content unless you follow some really active users.
And its a good way to meet new people as well, since you do not need know which individuals to follow, you just find people who post to your favorite hashtags most often.