I think this is overly simplistic compared to real world religions, which often have books full of complex and contradictory information, but if it's clearly 100% good and people are acting bad, then it's the followers more than the religion itself.
I would also argue that a statement like that is not a "religion", which is generally a system of beliefs as opposed to a single moral idea though.
I guess what I'm saying is that yes, we can blame the followers and not the "religion", but such a simplistic scenario is not generalizable to actual religions due to increased complexity of ideas and beliefs.
If you could somehow twist "be nice to people" to mean something harmful, then I suppose you could blame the religion, but that would be a tough sell in this particular case.
In this simple case, my first inclination is towards the proposition that the religion is what its practitioners do more than what its scriptures say.
Still, I don't think that really covers the situation well enough. I think I more want to go down the road of us having two religions on our hands here, one that has a bunch of followers and another that has few.
Of course that gets to be more of a problem with more complex interactions between scripture, practitioners, and other religions.
I don't know. It's a tough question.
The problem, then, is that if subjective worlds are experienced too differently, there occurs a breakdown in communication. -- Philip K. Dick