You must be new to all this.
Quality of shows don't matter any more. Tarzan is a humongous (sp?) piece of $#!%, but people eat it up because it's
a) Family appropriate; and
b) Disney has areally good reputation on Broadway, and everywhere else.
They [Disney] have awesome shows out like Beauty and the Beast and Mary Poppins, so people have really high expectations.
They must be very disappointed at the end.
Anyways, shows close because people stop buying tickets, not because of the quality.
Nowadays, if shows have a big budget, it's an automatic hit.