Personally, I like it because I think they're handling the characters' growth and maturation very well, how they abandon their youthful innocence to embrace adult maturity, and that includes dark things, like regression of bad habits, depression, bad coping mechanisms, and basically whatever happened in the Candy route XD

Also, the best thing is that it's clear that these things didn't come out of nowhere, and I mean it, if you reread Homestuck after reading the Epilogues and Beyond Canon, you realize that many of those dark, depressive, mature facets of the now-adult characters were present even in their childhood selves, but downplayed by their innocence and lack of understanding of the gravity of the consequences.

Plus, I really love the meta message that it doesn't matter if a fan work is canon or not, the important thing is that it's loved by the public, and that you don't have to adhere to the original canon. Basically, you can go as wild as possible with the characters as long as you love what you're doing and have something you want to share with other fans.

I'm really excited for the future of Homestuck, both Beyond Canon, the animated pilot, Hiveswap, and all the current fan projects (^///^)