The problem with much of the rubber roofs, which aren't really rubber in most cases and really are a form of vinyl, are that they hold heat. Just like vinyl siding they need to move, and if they are nailed too close together or too tightly you are most definetlya ssured they will warp/curl just like vinyl siding "oil cans".
Will the actual true rubber shingles last? Perhaps. Only time will tell. Aaron those tires sitting in tire piles are experiencing some degredation, I am sure we can all agree. I know the tires on my 94 look like crap and if I don't replace them some time soon are going to pop, and I am not talking about the threads, but am talking about the side walls. Rubber, like all things, ages and degrades.