Why doesn't skeletal brutes warcry detonate earthshatter and other mace skills?

The description for for earthshatter says warcries performed near the spike will cause it to shatter. Nothing suggests It can't be an ally warcry, based on descriptions it seems like the brutes warcry should work with all warcry triggered skills, but they don't. As far as I can tell the only reason it doesn't work is just because the Devs don't want it to, and isn't that just kinda antithetical to the genre? Having an alternative way to warcry with minions opens up potential mace/sceptre builds, why not lean into that, surely it's the whole point of sceptres being offhand.