Probably because how as the tie progresses, the objective standard of media and art has been destroyed and are now changed into a more "liberal" form. An art form where objective beauty, story thought, moral complexity, and clever references are replaced with a all giddy-show mediocre slapstick that caters to kids who has an attention span in less than 30 seconds.
Back in the days, kids shows show about how courage and heroism are important, how the world isn't nice and how some people can be a big jerk. How you should show disgust to those who fail or who did not contribute to society in a meaningful way. Now its about garbage stuff like accepting others or "always be happy" which doesn't portray how the real world works.
Back then, being tough on others and beat down degenerates so he could improve oneself is encouraged, now failing is encouraged due to mere reason like it hurts the audience feelings as if feelings is the most important thing in the world.
Conclusion is, people should be less sissy and the old-fashioned style of cartoon needs to be brought back. In fact i'd recommend a more gritty tone that shows how cruel the world really are to be an absolute best example of a show to educate the currently bratty children of the next generation.