I actually feel somewhat bad for you, OT, because I actually did the same thing to a guy just recently...
My reasoning was pretty damn simple. We talked often, texted daily, and hung out on numerous occasions. But the simple fact was that he was boring as hell. His only real interests were his parole and getting high ('cause those two together make a lot of sense) and all he ever talked about was how bored he was and how many hours of community service he still had to do. It was hugely depressing; I like being spontaneous and having fun, and a guy as uninteresting as he was proved to be a huge turn-off.
To be fair, he got the hint rather quickly, and I don't feel guilty about it. The simple fact was that I gave him the chance, and he didn't meet my standards (which aren't particularly high).
Every girl is different. As others have stated before me, I humbly suggest that you simply ask her yourself. Open up to her, but don't blame her or accuse her of anything or she'll likely ignore you completely; just tell her your thoughts on the subject and be honest. Nothing bad can come of it.