I agree, don't vape inside a public place unless they specifically allow it like some coffee shops. Most people don't understand vaping, and can be offended easily. Don't make it hard for the rest of us!
If the public place isn't bothered enough to put up a "no vaping" sign, then how is it hurting you? I see a few places with signs saying "Please turn off your cell phone" or "No cell phone use, please", or similar. That's because the base assumption isn't "Cell phone use is evil, you should know not to do it", the assumption is that if they want to forbid it, they will let you know. Back in the day, before smoking indoors was illegal, there used to be signs about not smoking. I find it hard to believe that they wouldn't put up a No Vaping sign if it was bothering them.
You claim that when I vape in public, I am "making it hard for you". How am I making it hard for you? What's the worst that could happen? The place could make a rule against vaping? Yes, they could. But you're wanting to make everyone treat it as if there is *already* a rule against vaping.
I'm fairly convinced that vaping in public helps people learn about it. If you stand outside and vape in areas set aside for smokers, you're not going to do much to educate John Q Public. And you're going to smell like the smokers you are hanging out with, which means that someone who knows you went outside to vape and came back in smelling like smoke is likely to think "That stuff smells just as bad as cigarettes".
I've also noticed a lot in this thread that people keep claiming "That's what kids do" and "He'll grow up eventually" and similar. I'm pretty sure I don't fit that "young hipster" thing you guys are picturing. I'm 53 years old.
I vape in public, in bars and restaurants and other places, pretty much every day. I've never had anyone complain in public, with the exception of a bar manager several years ago who sent a bouncer over to tell me "The bar doesn't allow smoking". When I went to talk to the manager, I didn't even get all the way to him before he saw my eGo and said "Oh, it's one of those, you are fine". And that's the *only* time anyone has shown any sign of having a problem with it in public.
Here on ECF, there are always people complaining about it. And they feel just fine with calling names like "punk", "stupid", "jackass", "d-bag", and worse. If I replied in kind, the mods would slap me down.
In the real world, it doesn't seem to be an issue as long as you use some common sense.