The only obvious thing that occurs to me is that bringing the bucket into the domain name puts it under the same-origin policy in the browser security model. Perhaps there are a significant number of people hosting their buckets and compromising security this way? Not something I have heard of but it seems possible. Makes me wonder if they are specifically not mentioning it because this is the reason and they know there are vulnerable applications in the wild and they don't want to draw attention to it?
I can't read what you're replying to, but it absolutely bothers me. The current scheme has this completely random double reversal in the middle of the URL; it would have been so trivial to just make it actually big-endian, but instead we have this big-little-big endian nonsense. Far too late to change it now, but it is ugly and annoying.
