"You're too nice" is definitely an excuse. She doesn't want to see him again for whatever reason, but she doesn't want to hurt him, and he <i>is</i> nice, after all...
It's one of those things that aren't intended to be hurtful that end up being hurtful. And people go weird places with it (like concluding that nice guys finish last, for instance).
I'm a nice guy. I'm married to a total babe, I've got a great job, and I'm up to big stuff in the world. So bite me.
