It’s not a request. It’s a dismissive demand.

> Please don't post shallow dismissals, especially of other people's work. A good critical comment teaches us something.

‘Citation needed’ teaches nothing but it is certainly very easy to type. It might be reasonable if there is a rule that citations are required like on Wikipedia, but here they are not.

The fact that some behaviors are popular doesn’t make them appropriate. Trolling is also quite popular and so are a lot of inappropriate behaviors.