I think the reason you're getting heat for this is that in your original post you mentioned that you thought it must have been stolen or thrown out after someone got kicked out of their home.
If you had acted more naive I expect people may still have bought the issue up but been a little more forgiving
I think some of the responsibility is on your uncle. I don't know where the law stands on finding stuff in dumpsters, so I'll neither condemn or approve.