That makes some sense. Maybe we are just keeping them until we have universal VLS cells with ASROC?I did some reading on this, and this is what i found out.
The Varunastra Heavyweight torpedo equipped on Indian warships has a range of 40 kms with a warhead of 250 kgs. Its comparable to the range and power of torpedoes that can be launched from enemy submarines. Thus, it creates a major deterrent for any enemy submarine to come close enough to target the Indian Warships.
The RBU6000 acts as a CIWS for enemy submarines with ranges as close as 1.5 to 5 kms. it can target enemy submarines as deep as 1 kms under the ocean and it can also be used to intercept incoming torpedoes or take on enemy divers.
Coming to Western warships, they carry Light weight torpedoes whose range varies from 10 kms to 25 kms depending on the torpedo model. Lower warhead as well.
The VL ASROC gives it some boost, that as a range of 22 kms+ torpedo range of 10 kms, giving it an effective range of about 32 kms.
This way, they keep most of their focus on the Air defense capabilities, allowing more VLS for SAMs. Meanwhile the Indian warships give a great amount of importance to ASW capabilities stocking the ships with bigger and heavier ASW weapons, looking at its adversaries.
Its the same concept as BrahMos. A bigger and heavier weapon that takes up more space and weight, but much more capable than the sorts of a Lighter Harpoon missile.
VL-ASROC has a big advantage in that it is much faster than a heavy weight torpedoes and this much more likely to kill a submarine.