Of course we'd prefer new raids to revamped old raids. But there's no equivalence here. A new raid takes an entire team of people weeks or months to develop. Rejigging the older raids should take a developer a few days to re-adjust the numbers. That's why people suggest updating the old raids - it gives us more stuff to do with minimal effort from BioWare.
Pretty sure it's more involved than that and that the devs have better things to do.
This is in no way a good idea.