|If health is like Irelia, by virtue of both being too good for how few drawbacks they have, why is nerfing these things not an acceptable solution?|
However - it means that Irelia needs to be basically gutted and completely removed from the game as an extension of this. It essentially means that Riven is still overpowered compared to Irelia - it's just that instead of Riven being far above Irelia - it just means that Irelia is so weak that picking her is instantly losing.
BoRK adds an intrinsic weakness to Health such that Armor does not have to be as crazy as it was in S2 to compete with Health.
If something has no real weakness - and you nerf the original so much so that you overcome the risk-aversion that players have to swap out - you still have the net power imbalance between option A or option B - option B is much much stronger than A. You've simply done so by making A suck - rather than making B overpowered - instead of ensuring that A and B both have real strengths and weaknesses.