Ashley Cole should have been booed because of his overall personality. He reportedly cheated on his girlfriend, asked for more money as a player than what people think he deserved, and doesn't have the most kind personality. His personality doesn't vibe with a lot of people. I think the booing was deserved, but it won't do him any long-term damage anyway.
I do not think anyone should be booed for trying something. Booing, to me, does not do a single thing but put someone down. Putting someone down in no way helps any situation. I believe that people should always try and lift each other up. If you don't like something then you should just not say anything or not pay attention.
Given a quick Google search I can not figure out who Ashley Cold is or why it would be appropriate to boo her. I would have to assume that it was probably not appropriate to boo this person because she more than likely did nothing to deserve such treatment. There's no point in booing people who haven't done anything.
The fanatics of Premier League football are a tough lot to please. Ashley Cole moved teams. Now, every time he is playing and gets a touch, the audience starts booing. Cole is no choir boy. He can pretend all he wants in the press that he has never done a thing wrong. However, this sort of treatment from the audience is only warranted maybe a few times and really only necassary when he's playing his old team. Booing every time he gets a touch? Indoctrinated much?
No, he should not have been booed at all. To become a professional football player, he had to be one of the best players in the world. He is extremely talented, and I bet that no one who booed him could go down on the field and play like him.