"By saying that Wuthering Heights in semaphore would make more sense than signing at a concert is an example of your complete ignorance on this subject"
Tell me why it wouldn't. Wuthering Heights is far less dependent on audio stimulus than a pop concert is. In fact you can read the book and still have a pleasant experience.
This is not a question of being right or wrong, it is a matter of opinion (to which, of course, we're all entitled). It is very unfortunate that some people are deaf and signing is a very useful way of enabling them to communicate effectively. But (and only in my opinion) signing at a pop concert is simply superfluous. It doesn’t, by any stretch, make the experience “as close as possible to that of someone without a disability” and that’s what the Equality Act sets out to achieve. If a promoter wants to provide the service, good for her or him. But the Equality Act should not be used as an instrument to force businesses to provide facilities which do not meet the requirements of the Act. Hopefully this will reach court and we shall see whose opinion is nearest the mark.