Comment by tsimionescu

It's not that powers of 2 are more important. It's that there will never be, for example, a RAM chip that has 32GB of RAM. They will have 34.36GB, which is an ugly number. But, they happen to have a very nice, round number of bytes if you look at them otherwise - they have 32GiB. And since these two numbers are pretty close, and the clean power of two one is far more natural for humans than the SI one in this context, it was natural to just call it GB.