Some hobbies aren't designed to be a functional lifestyle.
Hope you liked it.
"My Little Homosapien" copyright of Lauren Fist and Hasbeen.
EDIT: Some have criticised the fact that BonBon chose to leave Lyra without any indication that she tried other means of dealing with the issue. Now, where does it say that she didn't? Where does it say that she did? To be honest, that's not the point. You can decide yourself whether BonBon was a total bitch and abandoned her partner (who clearly needs someone there for her) or whether she did attempt to save their relationship, or whether she left because she was too afraid to tell Lyra that her much-loved fanaticism is making her unhappy... It really doesn't matter, so I didn't even give it a thought. The fact of the matter is, BonBon chose to leave because she can't deal with Lyra anymore, because she's so far gone from the pony she once was. If there's someone to feel sympathetic for, it's Lyra. She didn't realise the impact her obsession had on BonBon and her own life.
TL;DR - It's fine if you feel annoyed at BonBon for what she did, under whatever circumstance, but that doesn't mean it's okay that Lyra was acting as over the top as she was; this being the point.