Why is minion aggro so hard against Darius?

I play Darius a lot, and I noticed that when an enemy all ins me me compared to when I AA or all in, the enemy minions focus me SO much harder than mine do the enemy champ. I notice this on Warwick too. Even if the enemy team plays Darius, I notice that he is at a disadvantage with that. Whenever I play other champions though, the minion aggro isn't so focused. I think it has to do with the one update not so long ago about how single target spells also draw aggro too, but it's just a hypothesis. I've been wondering why this is for a while now. It's screwed me over on numerous occasions (and helped me too lol). Maybe it's just me that sucks with it but I don't think so because I haven't noticed it on many other champs.