Obviously if you are looking to be a ASW platform more helicopters and operating them at the same time is a boon over the Hyuga, though I agree more hyugas would probably be a better deal.
Where this really shines as far as its STATED mission is the offshore disaster relief role. Here space for hospitals and stores and refugees as well as the increased helicopter compliment and sortie rate are very helpful.
In reality it is definetly designed with VTOL capabilities in mind, the question is when will the Japanese get around to it for both procurment and political reasons. No harm in future proofing your designs if you can afford the up front costs of capability vacancy.
Here is another pic.