> Before we had a mosh pit people used to stand at the back, get very loud and upset people.

Get very loud? Upset people? Doesn't that tell you something? So you give them a place right in front instead where they can block the view? (And does being in front make them any quieter?)

> no one would use a mosh pit that was at the other end of the marquee

Why not?   

£87 each is a lot to fork out to not be able to see. I don't think there's any excuse for depriving your seated audience for the sake of the moshers (who misbehave if they don't get their own way, it sounds like). Was this event billed as a concert or a dance?

If you must have a mosh pit why on earth can't you allocate space to the side for it, even if it means a having narrower section of seats? You can't short-circuit one portion of your audience for the dictates of another. So move the sodding mosh pit if you absolutely must have one. And I really think you should have cancelled this one if the stage was the wrong height.

Another question this issue raises is, what do these dancers do when the music being played is quiet and not beat-driven, or is a slow song with words which are meant to be heard and understood? Do they stand silently and listen, or do they get bored because they can't dance to it and then start talking? Performers are usually sensitive to the mood of their audience so they may feel the need to just keep pumping out the rhythm, to the detriment of all other types of material.

I don't think catering to the demands of those who in the organiser's own words will "get very loud and upset people" sends an attractive signal to the rest of the customers, who will then HAVE to look at them, whether they want to or not, instead of the artists they paid to see.   

You need to rework this one, not make excuses. Those complaints are not whingeing, McFat. They're about not getting value for money. Even if that wasn't the intention, it's still what happened. Insulting everyone who disagrees with your opinion won't solve anything.