Honestly, I don't know of any time when introversion or extroversion was valued more than the other on a mass scale. A lot of very famous and successful people are/were introverted. Most of daily life responsibilities in the modern world are/were tailored for people to live more conveniently and individually. In America, the first president and most prominent founding father, George Washington, was most likely an introvert, ISTP. Thus, the ideals of the USA, and its culture, are going to be highly favorable on average to the ISTP-style of personality. Majority of the world's population, according to MBTI stats across the decades, show introverted sensors as having the majority share of the population, ISTJ+ISFJ together make up anywhere from 30-45% of the overall population. Extroversion preference, according to all this, seems like a relatively newer but not-so-surprising phenomena, since much of the mass media, since the arrival of the radio and television, seems to promote Extroverted lifestyles. The models for modern happiness and success seem to advertise a life of extroversion. In my experience I don't see extraverts any more happy or successful than introverts. However, what I do see in my purview is higher and higher preferences for Sensing over Intuition, in all sectors of the populace around the world. Only brief periods of culture, it seems, do Intuitives gain the upper hand in representing an idealized image for the culture. Beyond that, for the average person, I don't think introversion or extraversion really matters to anyone. Being a good person, paying your taxes/dues, treating people with respect, and always looking on the brightside are seemingly universally favored traits across cultures and time-periods, regardless of introversion/extroversion/sensing/intuitive preferences.