Remain is such a difficult place to win votes from - how do you present it as a positive?
Whereas you can say anything you want for Leave - anything could happen and it could be brilliant. Of course, it wasn't, and any campaign led by the massive blonde child and the snake oil salesman was always going to have a negative outcome for the British people.
The biggest issue is, and was, you should not let the public vote for something they don't understand.