What you are saying flies in the face of what bands said when they testified before congress about Ticketmaster [1]. I'll believe the people who swore under oath, thanks.
1. http://www.fivehorizons.com/archive/articles/testimon.shtml
In my experience TM fees are for TM. They may share with the venue, but the venue isn't sharing that with the artist. In fact they are taking a cut of the face value from the artist directly.
In fact I've even seen TM take a small percentage of the gross face value!
Regardless of which of these is getting the biggest cut of the "fees", the reality is that in most cases the "fees" are line items used to increase revenue without raising ticket face prices, and TM is not the primary beneficiary.
I read once that some parts of the US have laws requiring X% of the ticket price to go to the performer and that Ticketmaster fees were partly designed to allow the venue to charge its venue hire fees at a higher percentage than is allowed by these laws. Any truth to that?
If you're a performer and you want to sell tickets for a face value of "$50", but generate revenue at the $60 or $65/ticket range, you add on some fees and let TM take the hit from the fans for "gouging" them. It's very common.