As with many comments it can be genuine or sarcastic depending on the circumstances. I was a full time worker in a gas station. It was one of the classic ones with two hydraulic lifts and no convenience store. There were two part time guys who served in the same army unit together. They called most people "ace." Like how is it going ace? But I noticed they never called each other ace. Neither did they call the gas station's boss ace. It was obvious they used it as a term of derision. I guess it was sort of an "our unit against the world" type of deal. If you did not like it then do something about it was the attitude.
Anyway once the boss got wind of it he told them to knock it off if they wanted to keep working at his gas station. They both quit as soon as they lined up other jobs. It made coworkers unhappy to no purpose other than to make the part timers feel dominant.
That particular boss was a stickler for detail. But I did learn some valuable lessons in auto mechanics during my time there.