I hate this argument because you would just not count if brexit had been rejected as you wish it had been. You would just say "sigh it's normal, i'm happy people are not that stupid" and you wouldn't bother arguing with "stupid people".
Even if i wanted to argue on that level, you can say there was - 38% who explicitly said they wanted to leave - 37% who explicitly said they wanted to stay - 25% who had no opinion / didn't care
so it make absolute sense to leave in that case.
EDIT: To be clear i'm not pro-brexit, i just think "echo chamber blah blah biaised opinions" like this one are the reason people "can't understand" election such as brexit and trump and question the legitimacy...