I agree with the argument posed by rusinurbe and JonUrban. Here we have Steven Wilson submitting a contemporary masterpiece for consideration against a remix of a 40 year old classic which is no longer available. Maybe a rule change is in order. Shouldn't they require a Grammy winner to be available for listening? Now that the Layla remix has received the Grammy some folks may want to hear it and compare it to the submissions that did not win..
Also, winning a Grammy can open doors for an artist and assist in their further career development. Winning a Grammy can also change the direction the music industry takes. In the near term we can expect to see more artists like Adele get the nod from producers and fewer artists like Nikki Menage and Katy Perry. The Grammy is recognition of an artist's popularity and sales. Consumers vote with their dollars and the Grammy reflects the sales. Producers will follow the cash flow and book acts that approach the Grammy winners style.
I don't disagree with you from a philosophical point of view, it's just that it's not how the Grammy works. Specifically in regards to the Surround Mixing nomination and awards. The rules dictate that the nominations are made by NARAS (Grammy) Members from the Recording Sciences division - meaning producers, engineers, and the like (guys like Jimby). Final voting is made by the general membership of NARAS. The largest voting block of course comes from the major labels (Universal, Sony & Warners). Each member can vote for up to 20 categories or genres - so at the end it becomes a popularity contest. ES has been a long standing member of the Recording community and his work not only stands for itself but the majority of it has been done under the auspices of the major labels. It's not to say that an Indie candidate can't win - it's just if they are head to head with another major label candidate it would be more than likely for the major to win. Scheiner most likely was recognized not just for Layla - which of course has it's own recognition, but for the body of his work. If SW keeps at though, he'll get his shot in the not too distant future.
Forget about the argument regarding availability - it's not even a consideration - if it was released during the qualifying period - in whatever configuration, that is all that matters. And lastly, the Surround category is such an insignificant part of it all (except perhaps to QQ members) that a rule change is not even a consideration. Before you could even have an impact on a decision like that, you would first have to be a NARAS member in good standing - so quit your job, move to the city and intern for a couple of years with no pay and then if you're very lucky....