I can’t speak for the television industry, of course–but I suspect the main reason the programs you object to get produced is because they make money. And the reason they make money is because advertisers believe people are watching them. If you object to a particular program, therefore, let your local television channel know–and let the program’s sponsors know also. (Most of them can be reached through their Web sites, where you can also find the name of their president and their address.)
If every concerned person in America wrote polite but firm letters to the companies that sponsor such programs, who knows what impact it might have? If companies refused to sponsor programs that focus on violence or sex or other objectionable material, those programs simply won’t get aired. God told the ancient Israelites to “seek the peace and prosperity of the city to which I have carried you. … Pray to the Lord for it” (Jeremiah 29:7). Should we do any less?
Unfortunately, there will always be evil in this present world. Pray for your children, and do all you can to guide them and help them make wise decisions as they grow. Most of all, point them to Christ, because “Whoever follows me will never walk in darkness” (John 8:12).