I've noticed a few aggressive toots floating around disparaging people that don't "follow back". I strongly advise against telling other people how to curate their own timeline.
For some of us, following people comes with an associated mental and emotional cost. Following literally everyone back is unsustainable, unhealthy, and unreasonable. Please just focus on what you want to see on your own timeline and stop worrying about what's on everyone else's.
@sylphrin If I followed everyone back, I'd be following over 400 people, and that's just too much. I want my timeline to be something I can actually handle pls!