

Both male and female are supposed to be used as an adjective. For example “male model” and "female model’.
The problem is using female(s) as a noun. For example “I met 5 females in class today” which is just as weird as “I met 5 males in class today”.
This meme is almost certainly a criticism of the latter and as you much more concisely put it “Use “male” and “female” in its appropriate context”.
The reason this meme is phrased like this is because many incel groups use “female(s)” as a noun in a deliberately derogatory manor and people don’t do that for men.
Also clarifying the point like this would make the meme less snappy. Though I think they could put “as a noun” at the end
🥺