The Muppets are icon popular, but not actually popular. It's like Mickey Mouse. Everyone claims to love Mickey mouse, but when was the last time any Mickey production was released that was popular with a non-preschool crowd?
The Muppets are no longer popular for their humor. They are popular for the memory of their humor. Anytime they try to do something new people act like their childhood got ruined and every time they do the same old thing no one cares. Personally, I love when they try something new and even liked the 2015 series and both new movies. However, most people just don't care.
My hope is that the new Muppet Babies show will introduce a new crops of people to the characters and hopefully grow a new audience. My fear is that the new audience will only see the Muppets as children's characters. The show is done well and the people behind it seem like they really care about the Muppets so hopefully the new crop of fans continues to enjoy them into their adulthood.