I want to throttle them for taking what could be a genuine budding interest like yours was, and dooming it to a short life by intentionally giving bad information. I could care less that they sell these overpriced likely dead trees... what I do care about, is the mis-information/lie they sell along with it.
I have stopped and talked to one of these people... because one of them had a decent sized elm... but as soon as he figured out that I knew what I was about, he didn't want to have anything to do with me. They prey on ignorance.
Anyone who would say a juniper will grow well in a house is deserving of a good throttling in order to help balance out all that negative karma.