It would, but Amazon's AWS policy has never shown any indication of being managed like that. They'd done a reasonable job of keeping prices low, making them cheaper as the underlying infrastructure is cheaper to run and adding options (spot pricing, etc) that can reduce how much you pay dramatically in some circumstances.
The big reason is that S3 uses REST and a / request on a bucket is equivalent to the 'listObjects' API call. They'd have to figure out a way to deal with legacy clients who use this REST method to list a bucket.
The big reason is that S3 uses REST and a / request on a bucket is equivalent to the 'listObjects' API call. They'd have to figure out a way to deal with legacy clients who use this REST method to list a bucket.