Yes. There's an entire airline dedicated to it: SWA.

I like it when people have fun and enjoy their work but the clownery can border on appearing like things like being desperate for attention or the like when taken too far.

It can feel like the airline version of Officespace/hackneyed office humor that isn't actually funny because it's overdone.

I haven't seen this on UA and they seem to maintain a balance or decorum, if perhaps on a bit of the too starchy (or just grumpy on domestic mainline) side even.