So, companies are extremely protective of their image, brand, and identity. While we all know that vaping is OK, that it's very beneficial, that doesn't mean that companies view people sitting around in their establishments with tendrils of vapor wafting over their heads or flowing from their mouthes as a good image. Honestly, if I owned a store or restaurant that banned smoking, I'd likely be inclined to uphold that ban against vaping inside my establishment as well. My opinion will likely be an unpopular one, but I understand why businesses have a resistance and why it likely will never go away.
That being said, outdoors, or in places like lounges and bars (in which there are often more people standing outside smoking than there are IN the establishment) I'd say, if I was the owner of said establishment, I'd allow it. Those are traditional adult smoking places. Outdoors, there should be no question.
I'm not even going to say "oh but the children! We can't let children see!" Kids will eventually know anyway, or their parents will eventually have to explain addiction to them. I've never been one for sheltering my own children and I'm not really interested in sheltering someone elses. haha.
I'll actually stand behind any business that doesn't want to allow vaping in their establishments. I get why. It's an image thing, NOT a health thing. I know a lot of people won't agree with me though. I'm ok with that.