sat·ire
noun
the use of humor, irony, exaggeration, or ridicule to expose and criticize people's stupidity or vices, particularly in the context of contemporary politics and other topical issues.
I've seen quite a few joke posts in this subreddit tagged as "satire", none of which have been in an attempt to make any sort of critical commentary, as the definition of satire necessitates.
Very good catch, although to be fair the "satire" flag was made after a genuinely satirical post was submitted with a title that was quite alarming if it wasn't tagged as satirical.
But you are right, we've started applying it to every joke post even if it doesn't fit the definition of satire.
Good catch, thanks!