The Mail and The Sun are in business because they know how to make money, by exploiting certain attitudes. They reflect public opinion as much as they create it themselves.
This doesn't mean they don't tell lies. I think this is what is known as 'editorial line'. But then all the newspapers are guilty of this.
They are a measure of moral attitudes in this respect.
This is why I don't believe it should be banned, however I do believe that the right to protest and examine the morality of the editorial line is relevant. It can help to change public opinion, which in turn can force a newspaper to change its editorial line.
The biggest example of this, is how some newspapers have change political affiliation, in order to maximise profit.
Thats what it comes down to. This is a marketing ploy designed to encourage sales during the world cup (with the added benefit that it might help its image in certain groups). By showing it up to be a very insensitive marketing ploy, it might make it backfire and get them to rethink their policy.
A leftist policy, I believe would be to want a ban.
A liberal policy, I believe is to encourage debate and to gain consensus through reason so excess is self regulated.
Liberals are not necessarily left wing. They can be right wing (particularly with regard to economic policy).