Indiana Jones and the Let Down of the Century

I have't even seen it yet and I'm already disappointed. The reviews have been so underwhelming, and all reports from friends./co-workers/loud people on the tube have been decidedly less than enthusiastic. I just don't understand why Spielberg, Lucas, Ford et al would make such a hullabaloo - i like that word - about making a fourth film in what is one of cinematic history's greatest collections...and then go and balls it up royally.  Surely, SURELY, it wasn't all about the money, was it? 

Sure, it's wrong to judge a book by its cover, and so obviously I should go and see it before I knock it, and I will.  Afterall, it's still Indiana Jones.  But then that's just what they want isn't it. I'll be playing straight into their hands, the greedy little money-grabbers...