It’s because the webcomic called Homestuck doesn’t just appeal to the everyday person. It doesn’t attract the excited little kids like Spiderman does, or pull in the everyday middle-aged geek.
But it does pull in a specific type of person.
This fandom is comprised of all of the creators, imaginators, and manipulators of the world. The artists, the writers, the musicians - all of them are amazed and inspired by the creativity behind Homestuck. Even if they aren’t artists or writers or creators, they are those people who dye their hair blue and discuss Armageddon theories for fun and who made the sun blue and colored the grass red when they were little. All of those people who think outside of the box and color outside of the lines and are proud of (or at least comfortable with) their strangeness.
It’s why Tumblr is nearly crashed with fan responses and artwork and stories every time Hussie makes an especially good update (which is plenty a time). It’s why the last Homestuck album had 51 fansongs on it, with artwork to go with every one. This fandom so powerful in ways that so many other fandoms aren’t.
Spiderman doesn’t inspire people to create their own music to go with the scenes. No one wanted to make an anime out of the Harry Potter series just for fun. Neither Sherlock Holmes nor Naruto nor any of the recent Marvel superhero movies have inspired this much creativity or created this much attachment in their fans.
But the Homestuck fans aren’t all just randomness and weirdness like a lot of people believe them to be. They can actually be very intelligent. The theories of the time-travel paths and alternate universes behind Homestuck that the fandom has among themselves can be quite explicit and complicated. Discussions over the certain behaviors of this character and the quirks of that one can delve into certain specifics that many regular comic fans would not even bother with.
People create alternate versions of Homestuck characters while trying to keep them as realistic as possible. Crazy, random discussions taken up for fun can evolve into highly-debated ideals within the fandom. This fandom is home to so many creative and talented people that it is borderline ridiculous, but we would have it no other way.
So thank you to all of the powerful, weird, creative, random, talented, and inspirational people who contribute to the Homestuck fandom. We love having you around, nearly crashing servers and defending the over-zealous ones. We would have it no other way.