While the topic--whether to offer young relatives money for doing as we wish--was legitimate, the remarks leading up to the story were not. As a Baby Boomer, I was disappointed in your contempt-filled "Teenagers!" and similar remarks. You would not say, "Muslims!" or "Blacks!" or "Immigrants!" in such disrespectful tones.
When you treat a group of people with constant hostility and contempt, you should not be surprised that they don't enthusiastically adopt your behaviors and values. Perhaps a consistent attitude of respect would accomplish more than conditional offers of money.