Well, the ETM complaining isn't as big and seems only limited to their Facebook page. The "Hot and Cold" bit was on YouTube, which meant the outrage could be spread easier through the Internet. Let's be honest, not many people would check SST's Facebook page than their YT channel, especially if the latter has a celebrity appearance.
Also, the Katy Perry thing was about inappropriateness; parents saying kids shouldn't see that on TV. ETM is on the other end of the spectrum, where the complains thus far about it are kids who loved EW aren't so hip to the new segment. It's not something that parents fear is bad for them, just kids missing something they liked.