We are following the Halacha stated in the Rambam hilchos deos Chapter 6:
1)
It is natural for a man’s character and actions to be influenced by his friends and associates and for him to follow the local norms of behavior. Therefore, he should associate with the righteous and be constantly in the company of the wise, so as to learn from their deeds. Conversely, he should keep away from the wicked who walk in darkness, so as not to learn from their deeds.
This is [implied by] Solomon’s statement (Proverbs 13:20): “He who walks with the wise will become wise, while one who associates with fools will suffer.” Similarly, [Psalms 1:1] states: “Happy is the man who has not followed the advice of the wicked.”
A person who lives in a place where the norms of behavior are evil and the inhabitants do not follow the straight path should move to a place where the people are righteous and follow the ways of the good.
If all the places with which he is familiar and of which he hears reports follow improper paths, as in our times, or if he is unable to move to a place where the patterns of behavior are proper, because of [the presence of] bands of raiding troops, or for health reasons, he should remain alone in seclusion as [Eichah 3:28] states: “Let him sit alone and be silent.”
If they are wicked and sinful and do not allow him to reside there unless he mingle with them and follow their evil behavior, he should go out to caves, thickets, and deserts [rather than] follow the paths of sinners as [Jeremiah 9:1] states: “Who will give me a lodging place for wayfarers, in the desert.”
Credit: Chabad.org
We are living in a time where most of humanity does not believe in or follow the values of the Torah. We need to maintain a cultural distance from them if we are to remain loyal to Hashem & his Torah. Even if some individuals are able to to resist to assimilate with the masses around us, our community as a whole needs to isolate ourselves culturally if we wish to survive. The modern Orthodox community is a perfect example of frum Jews trying to take the honey of the secular world without being bitten by the snake of atheism that abounds. Many of their young people are leaving Yiddishkeit.