I've got to admit, i'm a bit divided on this.
Pulling it because of Youtube comments is really pretty stupid given the maturity level of a lot of people who post them...and for frog's sake - they can pull this clip because of Youtube feedback yet they can ignore the humongous amount of feedback that's steadily shown up for years under a wide range of clips on their channel from people complaining about how the show's been dumbed down or has WAY too much Elmo! That more than anything gets my goat.
I also don't think stuff outside of the clip such as some of Katy's other songs people may have a problem with shouldn't be as heavy a factor.
Yet at the same time, there was a certain amount of "what were they thinking?" involved with the original clip. I mean, yeah Sesame Street's always worked on different levels as per being entertaining for kids and adults but there's a distinction between that and bordering on adult entertainment if you get what i mean. People of a certain age can watch that clip and read all kinds of out there things about it and i can't believe no one wasn't aware of the various things that may be an issue when it was being produced.
Yes, kids are exposed to so much on tv anyway and as someone mentioned many SST aged kids saw Raquel Welch's number on The Muppet Show in THAT getup - but the big difference here is that TMS, while having much kids appeal was not A Childrens' Show. Sesame Street is very specifically For The Kids. So things like wardrobe, possible double entendres (which aren't always bad if they're smart and subtle and SST has done quite a bit), or ways things could be read, seen, or interpreted should always be on everyone's mind. You do things that are appropriate. ESPECIALLY because of the wide proliferation of stuff elsewhere on the dial, parents need that reassurance that Sesame Street and other "childrens' programming" are safe havens.
In theory if not always in practice, SST tries to appeal to adults so they can create a program that allows the adults/older relatives/caretakers to watch with the kids and enrich the viewing experience without making those older viewers want to gag or leave the room. If SST shows a clip that makes too much of the adult viewers uncomfortable and causes them to question whether or not SST should be a part of their childrens' viewing, then it's totally defeated the purpose. And if a (somewhat valid) uproar is made by adults upset about what the kids are being shown, Sesame Workshop does have that responsibilty to reevaluate it and pull it even if they feel the clip is fine but the ultimate risk of backlash is too great. The sad fact is if something offends too many parents or adults that may cause them to steer the kids away from SST altogether then what good does it do; the kids lose out because they can't watch, the parents lose out because they have developed too negative a view and Sesame Workshop loses out because they're blockaded from reaching their target audience and accomplishing their basic goals.
People taking care of children are rightfully under much scrutiny and have a large target on their back whether it be teachers, babysitters, daycare providers, sports coaches, etc etc and when you're one of the largest and most visible educators of children reaching millions (in the US alone), said target and scrutiny is much more intense. At the end of the day, you have to watch your back.
One of SST's best kept secrets is the blooper reels/gag films shown at their end of season wrap parties. Yes, SST is made by adults, creative ones at that, and there's a lot of joking around and blue humor that occurs strictly behind the scenes. The Katy Perry clip almost borders something that might be intended for that type of situation more than something for the show itself. Frogboy pointed out that yes, everything had to be planned and pre-approved which again leads to the idea of "what were they thinking" to begin with? Especially in the current climate of the budget cuts it seems even MORE attention and scrutiny would go into every filmed clip so how this made it all the way to final edit and almost airing is beyond me. It's not that there was one problematic aspect such as Katy's wardrobe (and really, they should have had more guts to say, "let's go with something else") but a whole bunch of little things that all add up together.
I don't like to see it taken out. But given how quickly and large the uproar occurred, i do have to support SW's decision to extinguish the flames before the fire consumed everything else. Plus given a lot of things about the clip that HAD to have been seen as risky, the fact it made it as far as it did regardless seems outrageous - enough people HAD to know how it may be seen by enough people as opposed to say the "I Want a Monster to Be My Friend" controversy. Plus they at least pulled it BEFORE it actually aired as opposed to taking it out of an episode after its already hit the tv screen.
There's been the rare occasional time SW decided to pull a clip from reruns (or at least out of rotaton for future episodes) in extreme circumstances like Chris Brown's clip (even though it either won or was nominated for an Emmy before everything happened), and it's easy to focus on those but there's many other examples of stuff that was left alone despite some ruffled feathers - the Families episode of Elmo's World has the briefest of clips of same sex parents in a montage, clips with Ellen Degeneris and Rosie O'Donnell remained not only untouched but in "heavy rotation" at the time when people objected to their being out and proud, despite all the crazy amount of attention (a couple years after the original airing!), "Pox News" remained untouched. The list goes on. They get a lot of pressure to cut things or not even include them to begin with and most of the time, they stay strong. It's only in the most extreme cases do they have to bite the bullet and make a cut.
So all in all, i don't like that it came to this or a lot of reasons behind it, i don't 100% agree it's the right thing to do, but i still have to support SW's decision on this.