Lol, you didn't say Aegislash presence in the metagame is positive, you said Offense would get better with an Aegislash banning and that Aegislash helps Balanced and Stall teams take care of that threats. So what? This doesn't mean anything, if Aegislash is broken the metagame should adapt to it.
Now to a relevant point does Aegislash have any reliable counters at all? Mandibuzz loses to Toxic, same goes for Hippo. You may say they can get through this with team support but reliable counters don't need team support. Krokodile is interesting, but lose to anything with Flash Cannoon. Umbreon is interisting but if it switches in a Swords Dance, bye. Heatran is good but doesn't like Sacred Sword which can be a 2HKO. I could talk about much more "counters" that Aegislash deal with X or Y set so its not reliable (sorry for my poor grammar, I am tape this on mobile.). Think about it; what mon is Aegislash best counter and does Aegislash have any set that can beat this counter?
Now to a relevant point does Aegislash have any reliable counters at all? Mandibuzz loses to Toxic, same goes for Hippo. You may say they can get through this with team support but reliable counters don't need team support. Krokodile is interesting, but lose to anything with Flash Cannoon. Umbreon is interisting but if it switches in a Swords Dance, bye. Heatran is good but doesn't like Sacred Sword which can be a 2HKO. I could talk about much more "counters" that Aegislash deal with X or Y set so its not reliable (sorry for my poor grammar, I am tape this on mobile.). Think about it; what mon is Aegislash best counter and does Aegislash have any set that can beat this counter?