It seems, for me, to boil down to: Do you think that the government has the right to restrict behavior, regardless of the fact that that behavior does no discernible harm to oneself or others. For some, the possibility of a potential for harm is enough, even when there is no scientific basis to believe that potential exists. That is what many of us are fighting. However, someone who believes that is not likely to change their mind, since reasoning has nothing to do with that opinion. It's also the basic idea for everything that most of us fight against. So yeah, frustrating.
Maybe I missed something, but I didn't see anyone put forth the "vape anywhere, even if it's not allowed" argument. What I see is a push against the "don't vape if smoking is not allowed" argument, which is something else altogether. If a business wants to not allow vaping, fine, they have that right. When the government gets involved, and suddenly it becomes a criminal act for me to vape in a car with my child present, I'm sorry, but you better have a good reason to make that call. I do not accept "It might be harmful, even though nothing credible has shown it to be."