Rules are being loosened. Folks are saying the Bible warnings about worldliness and sin must not be taken too literally. Parents might remove their pupils from our schools. The well-heeled professional people in our churches might decide to move their membership down to the First Progressive Church. We won't appeal to the mod, enlightened sophisticates if we have biblical standards for our people.
Legalism is the doctrine of salvation by good works.
Now I do not know any fundamental, Bible-believing preacher who thus is a legalist. This is wrong. But it is not wrong to have biblical standards. Bible standards are not legalism. Preaching against sin and warning our people about the consequences of sin and compromise are a command from God.