Interesting thoughts on the lexical scoping issue, and you're quite correct that a hash can have some advantages. However the main reason I used a different package was simply so you had an easy way of determing which subs were allowed to be called by the dispatch table. If you just define the subs in 'main' you have a potential security flaw, as any sub could be called. (Assuming you were dispatching based on at least mildly untrusted data of course).
In some cases you do need the power of a hash based dispatch, for instance if you wanted to assign a "security level" required to execute each sub, or complicated things of that nature. But for just doing quick "switch" type dispatches, this way is much faster to type and easier to maintain.