Is it wrong that I broke someone's heart by ghosting her?
What was the reason you ghosted her?
She was nice, but not interesting. She only talked about shallow topics.
If you didn't like her you should have told her. There was no reason to hurt her feelings by ghosting her.
I don't see why I had to be sensitive to her feelings.
Even if you don't care about her feelings, you should be mature enough to explain why you're going to stop talking to someone. Ghosting people is immature, and it doesn't allow either group any closure. Think about how you would feel if somebody that you liked abruptly ghosted you.