I could be wrong, obviously Salty gets more feedback from a range of sources, but from what I remember I don’t think the backlash was so much just because Heart of Rage was changed to be refunded/not consumed (making it less exclusive), but that some players had specifically spent 100+ Vault Keys before that change going for a second copy, only to have that decision invalidated.
This was probably compounded by being some of the same players who would have spent as many VKs (if not more) searching for their first copy under assurance that Heart of Rage was in there, only to have the drop rates increased as it was felt to be maybe a little too rare (likely as a result of their searching).
Both of these were ‘positive’ changes, but I could definitely understand those players being a little bit annoyed at the implementation and/or lack of making up for how they were affected by it. If that’s the backlash we’re referring to, I think the context is important.
Of course, maybe there were some players who really just wanted it to be more exclusive (or for it to be more difficult to have a full collection by what might then have been ~100 VKs or so) (I’m not sure of the actual drop rates, now or before the change).