You’ve basically invented a Venn diagram, put the etiquette rules you personally agree with in the “core” circle, put the ones you don’t like in the “grey area,” and then announced that this proves your conclusion. 😂 That isn’t an argument, it’s color-coding your opinion.
And no, “people used to think women should wear stockings” still does not establish that excluding someone’s spouse from a social invitation is EXACTLY the same thing. One concerns changing standards of personal dress. The other concerns how we treat other people and their established relationships when inviting them to an event. You can keep insisting they’re identical in capital letters, but the capital letters are doing considerably more work than the logic.
The funniest part is that you’ve simply declared inviting spouses “non-core” and therefore neither right nor wrong, which is the exact thing being debated. You don’t get to resolve the argument by moving the disputed issue into the convenient grey section of your homemade diagram and saying, “See? Grey!”
Etiquette does evolve. Nobody disputed that. The disagreement is over whether this particular convention has actually changed to the point that excluding a colleague’s husband or wife is now generally considered perfectly normal. “Some etiquette has changed over time” does not prove “therefore this specific piece of etiquette has changed.” Otherwise I can declare literally any courtesy I find inconvenient to be an exciting new frontier of social evolution.
Also, I’m crying at the journey from “should spouses be invited to weddings?” to your grandmother’s stockings, public nudity, micro skirts and apparently being able to see what somebody had for breakfast. This Venn diagram has become a crime scene. 💀