“let’s all wear black hats and voilà,”
I never said anything about black, and neither did the OP.
“I am all in for requiring socks in shul, by the way.”
Okay… Me too.
“everyone refers to the standard of the time of what is respectful clothing.”
I’ve not seen convincing evidence that this means we model ourselves after the goyim, as the Modern Orthodoxy likes to suggest. The minhag in the Torah world is still to daven in a hat and jacket. If that changes, you can say “times have changed,” but until then…
“Would you agree with this?”
Yes, that is exactly the machlokes.
“this becomes “no true Scotsman” fashion.”
As the great Papa Bar Abba once remarked in one of these CR discussions, all of religion is one big “no true Scotsman” shmooze. It’s redundant to pull that card.
“You simply declare that your community is the standard and, thus, everyone else is in violation of OC”
Not so. Litvaks, Chassidim, Sphardim dress differently and don’t take issue with the different fashions (for men anyway). This isn’t about different standards, this is about having standards vs. not.
“Of course, at some point – probably 18th century, Yidden clearly adopted standard Polish dress and then (some) refused to change it”
I don’t think this is “clear,” and I would, in fact, challenge the assertion that all Poles walked around looking like Chareidi Jews in the 1700’s.
“as we developed more sophisticated ways to deal with modernity.”
Which is what? Surrendering to secularism and liberal academia? If anything, enlightenment mentality is worse now than it was during The Enlightenment. For the record, this last point is not about davening attire.