many many reasons.
For a start when dance music went really big, it basically went pop music.
It was couritnf popularism, and well, pop music is a bubble.
It comes along, everyone goes "ooh, pretty" and the POP!!! it`s gone.
That and I think the myth of the superstar DJ slowly deterioated once everyone had decks and realised "shit, anyone can mix", and that again, it`s as much luck and blag and hype, as it is talent.
The mainstream turned it`s eyes back to rock.
The major labels lost out hugely during the independant label boom of the dance era.
The majors just couldn`t control this, despite trying to stifle distribution networks.
Rock bands are easy to control, burn the desperate bitches into a contract and CONTROL everything.
All these factors and some others contributed to the demise of dance music.
Right now I think we are experiencing a very odd time in techno.
A lot of the big names have moved on to minimal now, leaving techno with a big hole, which unfortunately is being filled with anybody who has the money to press a record.
Everyone with a copy of fruity loops and 700 quid to loaf is bringing out a label, the overall audio quality has dropped vastly, and their is more chaff to sort through. There are labels now that have no guidance from the old skool, big names, to keep the quality control up, which is a bad thing, but not permanent.
Just go to Juno and look at the amount of 001`s released every week.
How many 002`s are there though????
However, everything is cyclic, and techno seems to be back underground. Lots of smaller clubs with devoted fans who really understand the music, and who have the enthusiasm to keep the energy going.
I think some new movements will emerge, new sounds, within techno, and things might slowly build up again, all is not lost.
Meanwhile, hopefully the transition over to digital media will speed up so we can move out of this current limbo.