the issue is that there's a bunch of really dumb interactions with tribute passive that riot has let settle into balance.
aka, champs that can really, really easily trigger the tribute, sometimes multiple times
morg pressing w
malz press e
brand doing anything
in some cases it's a forced synergy like bard/lulu autos will trigger tribute twice.
compare this to someone who actually has to work to make tribute work, like karma or nami, where you have to land autos you have to land abilities; there is no free ticket to getting your gold.
and it's because of these super easy triggers that they can't really make it rewarding, because if they made it rewarding then all those super lazy tribute activators grow way out of line.
But there is a simple solution.
In pre-season the new thunderlords replacement works by limiting triggers to once per spell. aka you can't just cast a single dot effect and get 3 hits auto-triggering thunderlords. in order to actually get all 3 hits to satisfy the condition you need to actually outplay your opponent and actually combo them.
If they could take what ever effect they did to make that new thunderlords and put it into spellthief's tribute passive, where it will only trigger once per spell, then there wouldn't be this stupid disparity between champions and usage would be a lot more skill oriented and the item as a whole would be much healthier.
But for now we're stuck in possibly the worst arrangement for support items where the passive one for some reason generates the most gold than the one that actually meant to encourage healthy and interactive gameplay.