agreed. I remember back in late S2 early S3 I asked why we don't send duo lanes top and solo lanes bot to a friend of mine (he was plat/diamond rank and I was high bronze low silver) and he told me it was stupid and there is no reason to do that. then 6-9 months later, guess what all the pros were doin? lane swaps! lane swaps everywhere!
EDIT: but yeah, I think I understand why innovation is lacking in high ranks. it's because they prefer stability. they want to focus and hone their skills, and in a tumultuous environment with a lot of innovations means they have to relearn things constantly. If everything stays the same, you can come to expect certain things from your opponent, and if you know what your opponent is going to do, it makes it easier to plan your course of action and easier to guarantee a win based upon how well you execute your own plays.
Innovation introduces variables that can't always be taken into consideration, and thus the stability is shaken. Innovation is easy, adapting to that innovation is very, very hard.