Curate, connect, and discover
To be fair to Wrath, he had refused to ascend the throne until the end of Dark Lover, so he wasn't in position to change it before then. Lover Awakened, when he actually outlawed it, wasn't that long after Dark Lover (from what I can tell of the inconsistent timeline).
But hell, you think you'd have a bucket list of Things I'd Change If I Could after being a Brother for that long in such a shitty society and "stopping the slave system that victimized my brother" would be pretty close to the top...
The only way I will be ever satisfied with the brotherhood and Zsadist relationship is when all of them (specially Wrath) offers a rythe for allowing blood slaving to happen after fighting by his side for almost 144 years and still judge his PTSD