It's a safety issue, for some. Whether or not people are comfortable with what we're capable of doing doesn't much matter when you're dealing with a being like the Admiral, and a fair amount of people here are from worlds where abilities aren't unusual.

I feel that it should be handled on a case by case basis. If a dangerous inmate arrives with full power, there's a very real chance people will get hurt, especially considering that happens enough with the human inmates when they first arrive on board, but in the case of someone like Erik or Wanda, who know better than that, not having their abilities just adds insult to injury.