Dragon Event Overflow on our own servers
They already talked about the change. You get 1 guaranteed rare per dragon per account. Reason why they didn’t go with your suggested idea is probably either:
1- Don’t want break Guesting
2- Guesting wasn’t actually the problem at all, just the amount of loot was the problem. Considering that Guesting wasn’t a problem prior to the amount of loot change, this is probably the most likely reason.