In English, as well as most languages, pretty much ANY noun can be used as an adjective. (Or stick "ly" at the end and use it as an adverb too.) E.g., just so "woman" doesn't seem like such an exception, we use "man" as an adjective regularly in stuff like "man flu", "man boobs", "man trap", "man bun", "man ponytail", etc. Or in plural in stuff like "men folk", "men cologne", etc. Or other forms like "boy band", "boy school", "boy scouts", etc.
But basically any noun will do in a pinch, if you can use it as an adjective. In fact, it's normal grammar and used every day. E.g., just to list a few of the most common off the top of my head: "car sickness", or for that matter "sea sickness, "jet lag", "monitor glare", "music charts", "mouse wheel", "skull cap", "fanny pack", "bubble wrap", "internet browser", "cruise ship", "bed bugs", "infant mortality", "birth pain", "frigate captain", "manual page", "pocket protector", "microwave oven", "network cable", "bus ticket", "duck whistle", "varmint rifle", "rat poison", "cat flap", "dog whistle", "fox fur", "bearskin rug", "toilet brush", "kitchen sink", "shower curtain", "door mat", "winter coat", "beach body", "beer gut", "ski boots", "snow plough", "champagne bottle", "satellite dish", etc.
Sure, some of those add an unnecessary level of detail, and often in a derogatory manner. E.g., I'm not sure it's necessary to specify that someone has a "
man flu", since the virus is the exact same for all humans. E.g., I'm not sure it's necessary to specify that someone has a "
beer gut", since there are lots of other ways to get a liver failure that causes that shape, e.g., just by getting hepatitis or via malnutrition. (I'm pretty sure that those children in Africa that show up in photos with thin limbs and a huge belly didn't get that way by drinking beer.)
But none of those nouns needs any special permission or anything to be used as an adjective. It's just normal grammar.
But I guess when some people run out of other ideas to complain about, whining about being subject to the same grammar as everything else will have to do in a pinch
