horrendous class balance in PVP. resto druids and unholy death knights, as well as fire mages are just terribly broken and way too forgiving to play. I can absolutely delete people with my 350 ilvl fire mage just because of greater pyroblast not scaling with gear and being % based. also the best in slots are somehow not obtained in PVP like Gethikku which is a low drop chance from Kings Rest being BiS for warriors.
At least in legion you could actually PVP on your alts that weren’t simply fire mages.