75 years ago in the USA, almost every orthodox jew was really MO. Women didn’t cover their hair unless in shul, they wore short sleeves everybody hate cholov stam, nobody learned in kolel, everybody went to college and work, all had secular names, mixed seating by simchas (aguda convention use to have mixed seating) no shtreimels or beards etc. The world moved more to the right as the years passed. The MO believes if it was frum enough for 75 years ago its Ok now too.
Side note, the idea that a rav is someone who i ask anything more than halchaha aka das torah is also a new phenomenon that started roughly with R chaim ozer Z’l. The idea of das torah in litfisha circles is new. It used to be that you just worried about halchaha. (The chasam sofer and hungarain jewry had more since it was kehila based.)