I think Al is partially right: rudeness, from whoever to whoever, hardens opinion, it does not change it. But I disagree that it is most likely reason: I think few remainers have genuinely tried to understand the reasons people voted leave. Too often it is only asked to get a reason to insult (racist! Stupid!) rather than to find out what motivates people who do not fall into such simple categories. There is no point repeating arguments that were not convincing first time around. Remainers need to show remaining is a better answer to those concerns than leaving. Unless it does that, it will fail.