As much sense as that may seem and as much as I want to agree with you... I still can't. Sorry.
When Disney is fine with spending money for a brand new third Soarin' theatre, or a 3rd track for Toy Story Mania... Heck, Finding Nemo is STILL a good example here...
It's not that they wouldn't want to do it. It's just that they've never considered it. Nobody ever complains about the beauty and the beast show. It still brings in hundreds of people. Nobody mentions it. It's nearly invisible to their eyes.. So, why even think about it??
Whereas I remember many people complaining about how hot the Tarzan show was and how it was declining in popularity. Hence a reason Whu we got Nemo AND a brand new theatre.
Beauty and the Beast is like the least of their worries.. So they focus on what is giving them issues such as wait times for soarin and toy story... Closing backlot tour because of complaints and useless of it, so we get something new. Captain EO obviously got noticed enough to be replaced with preview films finally.
But beauty and the beast? It has JUST enough to keep park guests content compared to other issues. Therefore, they'll completely forget about its existence until they're either looking for a place big enough to put a full out frozen musical or until people start complaining about the show.
That's my view on the situation.. But that's really just me.