This is the MO argument justifying their way of life. They invented new hashkafos in the last hundred years, most of them based on the ruach of "enlightenment", like using secular names, being secularly educated, embracing non jewish culture, less respect for limud hatora etc etc. While the chareidi hashkafa has not changed since we were in egypt. We separate ourselves from the nations and put an emphasis on limud hatora. Nothing new at all. Yes, some of the yeshivos are structured a little differently, this is not "reconstruction" like the MO have done.
Was there a YU in Bavel? Did jews look like goyim 500 years ago?
They call themselves "Modern", a term that by definition means out with the old and in with the new. As if they can improve anything over generations of ehrliche yidden.
That's BS. Yeshivish right-wing Judaism is a construct that is just as new. Plenty of 20th century gedolim went by secular names when not in their yeshiva setting. I.e. Paul Medlowits, Issaac Hutner, and plenty others. It's completely disingenuous to pretend that your lifestyle is the same as jews 1,000 years ago, let alone 50 years ago.
PS: R' Shmuel Kamenetsky's wedding had mixed seating.