Considering the place had a store, and considering that a lot of people probably didn't pack luggage while being chased by hordes of flesh-eating monsters, why's it so hard to figure out that they probably got their clothes from the shop after they arrived and shored up their defenses?
Are you going to complain about Beth wearing a golf shirt?
If you're going to get upset at the writer's for not thinking things through, it's probably a good idea to do some of that yourself first.
I dunno man .... I think you have to leap through a lot of fantastic hoops to make some of the plot holes in this episode work. The most egregious of them IMO being an apparent literal class warfare battle between the country club members and the help, which I think most people would agree is absurd to happen during a ZA. Most people in such a situation would be motivated to work together since money and valuables would have become worthless.
America is very, very puritanical when it comes to sexual matters, even more so when the sexual matters concerning young women with older men (again, talking about characters here not the actors.) Hell, most Americans are perfectly okay with having guns around even if it means the occasional mass-shooting but think about letting two men marry? Well THAT we have to contain and stop!
I think you and some others have forgotten about the extremely popular film Dirty Dancing in which a teenager and her much older dance instructor have an affair. And in that film IIRC she hadn't even graduated high school. Also, Dirty Dancing came out over 25 years ago.
But here is a more up-to-date example, Frank Underwood's relationship with the much younger Zoe in House of Cards. Albiet Zoe was likely in her mid-20's while he as in his early 50's.