We'd rather give everyone

Shockwave is a cool ability, but if it is the ultimate AE tanking ability, that isn't really going to let dps warriors tank Utgarde. I also know plenty of warriors and bears that can get a large pull to stick them like glue even today. But it takes a lot of tab-targeting and a lot of skill. Skill is always going to be a component of tanking, but since you can't always gauge the skill of someone you don't know, we'd rather give everyone good tools to tank a 5-player run.