Good comments..Some causes to my opinion;
It's the lifestyle and the way kids grow up today.
Some examples where I think this won't be much different whether in usa or somewhere else.
1. Let's start with "dancing";
When I grew up which is ages ago (mid sixties), around 14 - 16 years old it was common habbit to "learn" style dancing! There were at least 5 different dance schools where we teenagers could go to.
I'm still living in the same area, and there is one Dance school left.
It's no common habbit anymore that teenagers learn "style dancing" .
In fact I think only a few percentage of todays youth can "dance" !
I look at my own kids.. no interest at all, because none of their friends go to a dance school.
One of the reasons; well there are other places enough where they can go to, while in "our" time the dance school was one of the few places to go out anyway and do your hunt
So one of the reasons you only see a few people on the dance floor if you are playing traditional styles (Which is what our arranger are very good at) they just don't know how to dance!

2. The huge amount of music played anywhere
(radio/television/computers)
While in our time there was a crappy radio and the upcoming popscene with vinly and occasionally (one or two hours a week on television) some top of the pops/hullabaloo or whatever it was called those days., today there is a 24 hour availability of all styles of music, so nothing sounds NEW for the audience anymore.
They are bored, which is in my opinion one of the reasons the house scene keeps very popular, where the enjoyment factor for todays youth has another dimension which we cannot/won't supply as arranger artist.
a. Feel the music instead of hearing it!
So damn loud that when I tried to go to a house concert "once" I was out in a few secs.
Somehow they don't realise they ruin their ears.
b. Allowed unethical behaviour (I really look old fashioned now, but that's how I think of it.)
c. Drugs abuse

mm... I can go on a long time with this...enough for now,,, just some 0,00002 cents...

(just listening to Allan Holdsworth while writing..)

Fred