There is a practical use - the representation returned is guaranteed to be true if the hash is populated and false otherwise. So you can test for whether a hash is empty very easily.

I used to have a pedagogical use for this information. See Re: Re: Shift, Pop, Unshift and Push with Impunity! for code that on old versions of Perl would demonstrate Perl's hashes encountering a pathological case. But that no longer works because these days Perl decides whether to split when it encounters chains that are too long rather than when it needs a new bucket. (This is IMO a very reasonable choice.)