It isn't needed because lemmy is literally full of the type of idiots who will never understand not sucking democrat dick doesn't mean you're automatically gobbling the conservatives, so they don't let a simple thing like sarcasm cloud their godlike omniscient knowledge of society. Your /s is not needed like a cherry wouldn't need to be placed on top of an ice-cream in order for the lemmy flies to wait for it to be eaten and shat out in order to pounce on the feces and gorge themselves. They would do it anyway, it's in their nature.