We are such fans of "the other story." Look at the news. We are always wanting to know the other side of the story, hearing the story from all angles, and knowing all the facets of what happened. With Wicked, we get that. Not to mention we get some new fun songs to add to our personal mantra repertoire.
The Wizard of Oz is now 80 years old, but I believe it's still as relevant now as it was when it came out. It's the rare film that still captivates audiences even now, even if the fame of Wicked has spread wide. I will tell you that I can't watch it the same way as I could before I saw Wicked. I mean, the entire time, I'm trying to put the two stories together and make them make sense as one giant story, which I think is okay. I don't think it's a bad thing to view them as one big story. That connects new art with old art. Without the first film, the second book and subsequent musical would never exist, therefore forever connecting them together. They are unable to be separated from each other.
I will say this. Watching The Wizard of Oz again as an adult it completely worth it because there are all sorts of things you notice now that you wouldn't have noticed as a kid. For example, when the prissy little Lion is singing his song in Oz and he's got that cape on, there are bluebonnets in the flowers. In the moments before Elphaba...I mean the Wicked Witch is standing on the house and throws the fire at the Scarecrow, there is a GIANT bird in front of that house. Who knew there were Emu-like birds in Oz. This isn't Yemen. It's Oz for goodness sake.
So be it as it may that Wicked and The Wizard of Oz are tied together, that's okay. It just means that the story is that good.