People get upset about relatively unimportant things. I'm pretty sure sexism exists and is bad, but this is just... not it. It's a dumb meme, that's all.
Again, it's not for you or me to dictate what is actually important. Not important to you is not the same as being objectively unimportant.
for one thing, a use of a meme doesn't infringe on anyone's rights
We sure can.
You're talking about the meme, the Swedish ad watchdog is talking about the job ad.