I personally think that Elmo didn’t ruin Sesame Street, but it was the characters introduced for a progressive message that did. Abby Cadabby was introduced as “good female representation”, but is nothing more than a one dimensional stereotype. Julia was introduced to “destigmatize autism” but is high-functioning and misleads the viewer into thinking that all autism cases are as mild as she is. In recent times they have added muppets of different human races whose main purpose is that they are “that race”. It isn’t necessary when SS targeted these issues before, but like all long-running shows, it has become repetitive in its stories.