Infernal Hordes aren't good enough
The main issue is that at the end of the day, Infernal Hordes take a lot of time and their rewards do not match the time investment. Because of Warplans in Lord of Hatred, the increased drop in infernal compasses also does not provide much in the way of excitement, as players will most likely already be stockpiling dozens of them. While it's a nice upgrade and a decent event for the increased Aether and Chaos Waves (which make the hordes much more lucrative), the community has been clamoring for some QoL and improvements to the base game mode.
