Why do you have to take such a tone? Can we not disagree and argue without adhominem attacks?

Your argument is a fallacy. In any division there are going to be those who agree and disagree with the outcome. Of course the people who get what they "wanted" don't argue against it. But they also shouldn't argue against the legitimacy of those who don't to continue to argue their point. That is the difference here.

Yes, there was a vote on an advisory referendum that had not specific details about what the outcome should be. What does that make legitimate?

If Theresa may had decided that to leave the EU we had to go to war with Europe, would that be legitimised by the vote?

This argument is about the terms of any such approach and how to legitimise those.