When Rose said she wanted to rip Sburb apart by the stitches, she wasn't kidding. If she's blowing these ruins to smithereens, how is she supposed to learn anything from them?
Is she, perhaps, provoking the game? Maybe ripping apart her Quest triggers some sort of defensive action from Skaia, and that's what she's trying to study.
It's also possible that this is her Denizen's Palace, and killing her Denizen early is just the most direct way to break her Land completely. Denizens are strong, but this Horrorterror-amped Rose is the strongest Player we've ever seen.
GA: [...] This Is A Difficult Topic For Me To Broach
GA: For Reasons That You Probably Wont Understand
TT: You're rambling again, Kanaya.
Before Hivebent, Rose didn't even know Kanaya's name - but now she knows her well enough to read her mood. We've missed a lot of offscreen conversations, and for once, I do not accept this. Show me their slow-burn, Hussie!
GA: Ive Just Been Meaning To Say
GA: That I Read Your Instructional Guide
...this is a conversation I'm glad we've skipped ahead to.
You are suddenly the troll girl.
In a different game session.
In the past.
Well, we're in the past, I guess. It's after the demon attacked, but before Kanaya made friends with Rose - which doesn't narrow it down much. After all, that's pretty much all of Project Trolling.
GA: Your Speech Was Really
GA: Emotional
GA: I Just Wanted To Ask You Something In Confidence
GA: About The Humans [...]
GA: Are You Sure Theyre Responsible For Our Misfortune
CG: YES. THERE IS NO DOUBT ABOUT IT.
GA: Was It On Account Of Malice Or Incompetence
Kanaya was asking the right questions - but she was a little too quick to take Karkat's word for it. He's blinded by rage and caliginous attraction, and hasn't yet realized that there are other agendas at play in this session, besides its Players.
Personally, I doubt the Mistake was caused wholly by incompetence. I'm almost certain it was the result of interference - from Doc Scratch, the Horrorterrors or some other party. Someone wanted this Rift open, and it wasn't the kids.