Having previously played in a function band for a number of years. I was constantly amazed at the lack of respect payed by the venue management to the band. Managers saying 'Oh you don't have drums do you. This venue isn't good for drums' - "Well you booked a band with drums".
The haven holiday camps were dreadful for it. The would constantly see the band as an inconvience, we were asked if we could pack down between sets as they usually do 'a game show on stage' at 10pm for 15 minutes. Being told to arrive for 4pm to set up and then having to spend ages hunting down someone to let us in. Years ago you would get accomodation paid and a breakfast. Then they gave you subsidised acommodation and a reduced price for breakfast and in recent years they expected the band to book accodomation at the standard rate with no discount on food.
Last summer on a holiday at one myself I saw Heatwave play a cracking set at a Haven with a phenomenal bass player only for the compare to be pretty rude that people could now get back to having fun as he cranked up YMCA out of the DJ booth. I just felt so embarassed that a band who had performed their socks off got treated in such a fashion.
Or the venue that had a DJ box taking up 2/3rds of the stage, when we asked to have some of the equipment moved so the 4 piece band they had hired could set up retorted "Well we had Rod Stewart last week and he didn't have a problem" said Rod Stewart was two chaps (one singer and a guitarist) with backing tracks.
Also go to agree Bilbo - backing tracks and Jazz is a dreadful combination, but the publics understand of the music is poor. Loads of weddings I've played have had a chap in suit doing a very mediocre sinatra impression over some stiff limping backing track with keyboard horns FFS and people lap it up. In terms of earning from a live music situation - one chap with some backing tracks is going to earn a lot more than a band and only people with interest in the music, which is the minority, will care.