>>17249500Defog only lowers evasion by one stage. So assuming that you do come across a evasion abuser, you will have to waste a turn switching out your Defogger on them and they would probably see that coming and use DT again which gives them +2 or Minimize a +4.
And a smart person wouldn't send out their Blissey or Chansey( Because they are the only Pokemon with Minimize that is weak to Aegislash's Sacred Sword) while you have Aegislash alive. When Aegislash faints, what's stopping the opponent from raising their Blissey's evasion?