Just because music can be 'fun' without a substantial message doesn't excuse inanity.
Nathaniel's "Live Louder" is a perfect example. "Live Louder", although it is a meaningless song, really just for dancing, still has musical substance, movement, transition, soul.
"Blah Blah Blah", on the other hand, is utterly inane. If you compare these two songs, it's completely obvious that "Live Louder" has substance whereas "Blah Blah Blah" is infantile gimmickry.
"Live Louder", in other words, is worth listening to. It caught my ear and I stopped to listen to it when it played in the gym today.
So you see, just because a song isn't serious doesn't make it inane. Blah Blah Blah is inane because it's a cheap gimmick. The example of this post's comparison clearly illustrates this.