Because it's for preventing the spread of the virus so we can get it all under control. It protects other people from you, more so than protecting you. That's why we need everyone to wear one; if somebody doesn't wear a mask, they just screw everything up.
Ok, Imgflip is obviously going to trash again. If a good, laughable meme doesn't get noticed at all, but a beggar can post a picture of a carpet and get 1100+ upvotes, that's a sign our community is going bad.