You couldn't be more wrong, the reason Disney is closing these clubs has almost nothing to do with the decline of people dancing and has almost everything to do with Disney being able to maximize the profit from every square inch of developed real estate.
What they have decided is that it is far more profitable to have generic retail or dining outlets come on property, pay Disney rent and a portion of their profits rather than run their own entertainment, pay for staff, inventory and receive no rent for the space.
This mentality has taken hold of Disney management with a vengeance. All you have to do is take a look at the number of entertainment options at Disneyworld that have been cut back or have disappeared altogether with no replacement in sight over the last several years to confirm this.
The days of substantial free entertainment being offered at any Disney owned property be it parades, shows, rides, fireworks etc are coming to an end and quickly. Hence the introduction of more and more hard ticket extra cost events.