The revisal craze combines the feeling of:
a) minimizing risk - revisals are done on shows that probably worked, or at least partially worked, before. This is one of the reasons people are so hot for good catalog shows too. If you loved Coca-Cola before, wait until you taste New Coke!
THE UNSINKABLE MOLLY BROWN recouped on Broadway and had a healthy tour, stock and amateur life before becoming one of those "shows no one does anymore" like BELLS ARE RINGING or WONDERFUL TOWN. The film was a massive hit, the 12th highest grossing film of the year even as musicals were falling out of favor. It's the last real MGM musical.in a lot of ways. The property has a not insubstantial amount of success in its past; revising a MOLLY BROWN or PAJAMA GAME is NOT the same as revising WHAT MAKES SAMMY RUN? or MACK AND MABEL or something that's always been a commercial flop.
b) looking down your nose at the past - it's so much easier to congratulate yourself on how enlightened you are, and say "that hoary old book, it'll never do now, oh, it's so un-PC and simpleminded" than to write your own show and score from scratch about the same historical character, or using the same storyline. Rewriting a dead writer's work meets no resistance, and if you flop with your new version your out clause is to say "well the problems with the original book went deeper than we thought."
c) putting your own stamp on the work of the revered deceased - the rewriter-as-rescuer, as the person who knows better than those people back in the day ever did. Let's throw out all that old stuff and put in some of MY stuff, not only is it as good as what those dead guys wrote, it's even BETTER, but I'm still going to help myself to whatever lines and songs of theirs I like so I can co-opt the show's original success for myself and my career.
The Debbie Reynolds-Harve Presnell 1990s tour (there's a good bootleg of it) did a good job of cutting the score and streamlining the book. It also put in a flashback to accommodate an older actress playing Molly. Interestingly, some of the songs that weren't sung in the film made their way back into the Reynolds/Presnell stage version, and they put in "He's My Friend" from the movie. Meredith Willson lived till 1984, and there was nothing stopping him from revising his score for 24 years if he'd wanted to.
The original TUMB gets off to a rousing start, and the Act I score is not bad. It's in Act II when the plot slows down and there are some real dog songs that the show starts sinking under its own weight and you start looking at your watch. Even in the 1960s critics were pointing out the flaws in the story, and the score isn't written in a style so that it will match a book that has had a modern sensibility grafted onto it in a rewrite, no matter how many interesting actual historical facts get namechecked. It's always been an awards bait show for the actress playing Molly, another role for your actress who played Annie Oakley, Nellie Forbush, Sally Adams, or any number of roles like that. The person who mentioned Reba is right; MOLLY BROWN is nothing if not a celebrity appearance show. So it burns hot with charisma and choreography (when you have Peter Gennaro) and the rags-to-riches spectacle of it all. You keep it loud and big and as sincere as you can, and by all means, keep it moving.
This MOLLY BROWN revisal, which I haven't seen and know nothing about, has been in development since 2009. Review of 1990 Debbie road show version at link.