Blah, I'm guilty of saying e-cig to building managers. A while back at work, the smoking section of the parking garage was being used for a pot luck, so I vaped on one of the other levels (where smoking is not permitted). One of the building manager people said if I wanted to smoke to go to blah blah 500 feet away from my work. I started by saying, "its just a vaporizer, I'm not violating any building codes or anything."
He was confused so I just said "It's LIKE and electronic-cigarette." So I'm taking baby steps with the transition by differentiated my PV from e-cigs.
The man ended up just congratulating me for quitting smoking. When my ... is on the line at work, I don't want to get into a heated debate with management over what I'm doing (they'll just dismiss the idea all together as is their right). So if calling it as a similar device to e-cigs helps me from being hassled that tends to be my go-to phrase.
If its in casual conversation with another person where I don't care if I get crap for it by a store clerk, I'll just insist on calling it a vaporizer.
To go on topic with retailers screwing things up with marketing, I don't completely agree with that. I live in the San Francisco (bay area) of California where vaporizing is associated with vaping 'the green stuff'. Vaping / smoking the green stuff in public is very common here, I come across them several of them every day. So, for me, its a lot better to be associated with vaping e-cigs than it is vaping in general. It's gotten worse with the 'green stuff shops' selling cartos with 'green stuff' juice.
Hope that makes sense, I'm pretty sure we're not suppose to be talking about certain substances on this forum so it won't show up on google so use your imagination on what green stuff refers to.