You're right about one thing: Crude and blasphemous language is certainly more common than it used to be. It seems like it's almost impossible to turn on the television or watch a film without hearing language that would have been banned in previous generations.
But you are wrong in saying the Bible doesn't mention this. For example, one of the Ten Commandments tells us not to use God's name in a thoughtless or irreverent way. It warns, "You shall not misuse the name of the Lord your God, for the Lord will not hold anyone guiltless who misuses his name" (Exodus 20:7). In addition, the Apostle Paul urged Christians not to use crude or inappropriate language. He wrote, "Among you there must not be.... obscenity, foolish talk or coarse joking, which are out of place" (Ephesians 5:3-4).
Why does the Bible urge us to avoid this kind of language? One reason is because our words are a reflection of our hearts and minds. If you constantly use God's name carelessly, it indicates He isn't important to you. If you constantly use crude language, it indicates your mind is filled with unclean thoughts.
I pray you won't laugh this off, but that you'll face your need for God's forgiveness and cleansing power. Begin a new life -- the life God wants you to have -- by asking Christ to come into your heart and mind. Then ask Him to help you submit every part of your life to Him -- including your tongue.