Nice little mention on a person's blog online:
"Add into it discovering what an awesome guy Richard Hunt was, too, and how young he died, and it gets a little sad seeing their work. But then they make you smile or laugh again, so it somehow works out okay. I can't figure it out, either, so don't ask."
I definitely understand how this person feels. Depending on your point of view, it sometimes feels like the Muppets were on top of the world, but ended on a tragic note. It's sort of like the Beatles break up; you wonder why it had to happen this way. It didn't seem to make any sense.
But I think this blogger has it right, as long as your still able to smile at the work, perhaps that is what really matters. I don't think they'd want us to be too sad when watching their work. And I'm reminded of one of those letters from kids, "I guess they needed Muppets in Heaven."