My theory is it's because the current generation never had to deal with any uncomfortable or negative emotions. Mommy and daddy would always step in and take care of it for them. They were taught that negative emotions are bad to have, so instead of learning healthy coping mechanisms and how to deal with these feelings on their own, they were taught that feeling anything except happiness and love 100% of the time is unacceptable, and anything that makes them feel bad or question their values needs to be censored.