I don't think anyone has a problem with you taking that rope. In fact, most if not all people glad that you did.
I think just about anyone who ice climb has a problem with you being on that route given the condition it was in. But since I wasn't there, I don't know the detail of what makes you decided to climb that route when it's clearly falling down.
So if you want to talk about mistakes. The mistake isn't that you took the rope, it's that you were climbing the falling ice route in the first place.
I think you are entirely correct. I had no business being on the route in the first place, I was a fool to even try it. However, I do think it would have been quite safe for a more experienced climber, no?
The Mohonk Mountain House and the Mohonk Preserve have done a great job protecting the environment thus far, but ... it's all down hill from here http://youtu.be/9AU8fMo8v4k.