While I respect everybody's right to their opinions, I'm shaking my head over all the hatred and vitriol on this thread, all because The Muppets have dared to appear with people who some of us don't admire, respect or enjoy in other mediums.
Yes, it's hard to accept that occasionally our beloved gang might show up next to allegedly-marginal talents, but that's the risk that a franchise like this will occasionally run when it's attempting to stay in the public eye, especially over the 58 (58!) years The Muppets have been in existence.
I personally wouldn't walk across the street to see One Direction if you paid me, but I'm delighted that Kermit and Piggy wound up in even a brief portion of what I suspect was a high-viewership broadcast. (And why has nobody mentioned that at least one of the band members seemed thrilled that The Muppets were in on it?)
We can gripe about 1D, Lady Gaga, Miley Cyrus or the other Studio DC guests but I'm sure eyebrows were raised about similar flavour-of-the-month TMS performers (Leo Sayer, Lola Folana, Shields and Yarnell) or hitmakers that took the Muppets out of their supposed comfort zone (Alice Cooper, Debby Harry, The Artist Formerly and Currently Known as Prince, etc.)
I have no issue whatsoever with Rob Schneider being in MFS. He's made some questionable career choices but he didn't ruin the movie, not by a long shot. In fact, at the risk of being too optimistic, my list of co-stars that have genuinely dragged down a Muppet production is quite short (and it usually begins and ends with Andy Kaufman/Tony Clifton on The Fantastic Miss Piggy Show in 1982).
As for the characters appearing in "questionable" material (The Bachelorette) or with "questionable" stars, chew on this: The youngest TMS guest star was 15-year-old Brooke Shields, who shot her "Alice In Wonderland" episode the same year as a salacious little movie called The Blue Lagoon landed in theatres.
Apparently Jim Henson was able to see beyond a star's on-screen personas and off-screen personalities to pick the right people to work with The Muppets. You're free to disagree, but I think this legacy has lasted to the current Disney regime and will help prolong the franchise's shelf life for years to come.