Bottom line- If you were at a friend's house, and in spite of your best efforts to educate your friend, they ardently wanted you to not vape in their house, you wouldn't stop being their friend, and tell other people not to be their friend. (at least, I hope not...)
On another note, a lot of it is knowing the people. I don't vape at my nearby Starbucks, inside. I have before, and the worst I got was funny looks. I don't now because they recently changed Managers at the location I frequent, and I haven't really warmed her up to me yet. Outside the starbucks, though, is altogether different. I vape (and i still smoke a lil too) openly, and unabashedly. I don't throw it in other people's faces, but I try to be a polite person, generally.
A recent exception: do you remember those militant non-smokers? You know, the ones that would walk by, mock-coughing and swatting at the air? Saying things like, "I can't believe it's the year two-thousand [whatever] and people still smoke!" ? (i've had this passive aggressive piece flung at me, verbatim). I walked right up to the MFer and blew vape in his face. Needless to say, he was more than a little confused by the strong Cinnamon aroma that billowed out of my mouth.
But yeah... consider the way you presented it before you decide THAT is the reason you're gonna boycott Starbucks. (I'd boycott them on corporate principal alone, but there aren't any other coffee houses around here
)