Actually, Aurorus can be good under some circumstances (like every Pokemon ever). It just needs a lot of support and the opportunity to set up.
At max speed, Aurorus is at 236. After one Rock Polish (x167%), it'll be at 394 which will out speed Noivern, the fastest Dragon type. Rock Polish is a good set, since it can ditch Choice Scarf for Life Orb.
It also has a decent movepool, with access to STAB Freeze-Dry to deal with water weakness and Flash Cannon for coverage. Downside is that Ancient Power is it's most powerful special Rock move. But even with 2 x4 weaknesses, Aurorus does have decent bulk (123 base HP), so it has a good chance of surviving a x2 hit.
However, it's outclassed as an ice user the higher tiers when there's Protean Greninja, Weavile, Froslass, Mamoswine and, it's main NU rival, Choice Scarf Jynx. With the right team support, IV breeding and EV training, Aurorus can be a good sweeper, but you need to build your team around it in order for it to work well.