"Perhaps Wildhorn is off the list because the man is a joke among the real talents in the theatre community."
... I love how there are plenty of actors who are thrilled beyond belief to be working with Frank Wildhorn and to sing one of his scores... Despite flopping every production, he's still getting his shows produced not just in the United States but around the globe, etc.
I'm guessing you think all of these people have no talent since they joined Wildhorn shows by free will: Terrence Mann (2-Tony Award nominee), Christine Andreas (2-Tony Award nominee), Carolee Carmello (2-Tony Award nominee), Melissa Errico (Tony Award nominee), Tom Hewitt (Tony Award nominee), Rachel York, James Barbour, Kate Shindle, Christiane Noll (Tony Award Nominee), and the list goes on...but moving on!
"And all his work is so poorly conceived that his arrangers have to re-write everything. The fact that Jeckyll, as you report, seems to have so many productions (although I've never heard of them) just goes to show that people often love sh*t."
...Jekyll & HYDE is legitimately one of the most performed shows, I have no idea how both of you have avoided seeing it in the regional theatre circuit... Also: His arrangers do not re-write... not sure where you got this information. Yes, perhaps tweak an ending or a beginning every so often, but nothing major.
The Third National Touring Production (Non-Eq) which went out in 2000 and played through 2001, which paid back (It used the same costumes and some of the same sets, but altered them/simplified them a bit. Apparently DVD sales also helped a bit (although I don't see how necessarily), as the producers (& David Hasselhoff) produced the filmed version as well.
It is not the creators that change it, it is generally the DIRECTOR of the production which Frank gives the liberty to tweak, add or remove things, or rather the major productions. Almost like a revival of the original with every new production, something changes. Sure there's the definitive production that is licensed, but I like the fact that you could see the show on Broadway with one director's take, and then see it with another director and see a totally different take.
There's no winning so I guess I'll stop

. I do legitimately think that Frank is an important composer, whether it's the material, flopping everything, opening & reclosing a show 3 times, the elegant staged productions, whatever... Frank writes for his fans and he's still got a slew of them out here!