The short & sweet of it is that you are incorrect in your assumption. And I really think it's a little bit funny that you think you can say with so much certainty what people do & don't do or what they do & don't notice when you're not there to witness it.
Yet you go on to assert the very thing you just accused me of doing -- deciding you know for sure you aren't bothering anyone.
Personally I am way more concerned about people who believe I am incapable of judging for myself what is & isn't a problem for others than I am about vaping bans. In fact I'd have to say that the worst criticisms of my vaping habits have come from people in this forum & not from anyone I've met in any RL social situation.
And I'd have to say this is a conveniently self-serving and narcissistic POV in the extreme, that you can judge what does and does not bother others - particularly in a movie theater (the context here) when you can't even see the people directly behind you who are most likely to be annoyed and notice what you're doing. Even if you sit in the back row there are people to either side. And you certainly cannot assume you aren't bothering anyone based on saying "no one complains." Polite people won't tap you on the shoulder in the theater and say, "Hey buddy, that's annoying me and it really isn't even allowed, so do you mind?" They won't do that because only an a-- would be doing something annoying to begin with, so telling them to knock it off likely won't do anything but ruin the entire movie experience by enticing a confrontation.
As for getting more guff here than IRL, that's why. It is safe to tell someone here, "I don't think that's a good idea," whereas IRL that could cause a fight. Moreover, people here are interested in protecting the right to vape and will tell you or any other member when they think something might be good or bad -- based on their opinions, and we have many opinions.
That doesn't mean I think we have to please all of the people all of the time. It is a diverse world and people have to stop applying their prejudice against smoking, against vapers. People have to "get over it" in some cases, like in the case of outdoor public places. But in a movie theater... imho one should step outside the theater into the hallway if they really can't go 2 hrs without a vape.