I could say that I didn't like the episode because it focused on a character who did not appear until the season 3 finale and was originally intended to be a guest star. I could say that I didn't like this episode because it featured a plot you might see on an episode of Jessie or Ned's Declassified with a girl feeling down because she was not invited out with her friends. I could say that I didn't like this episode because Raj consistently was given the last joke of a scene, usually reserved for the best line, but he did not say or gesture a funny thing all night.
I could have said all of that, but I won't. I just think that this episode flopped because it was not The Big Bang Theory, it revolved around the female characters. This was a backdoor pilot for a spin-off starting those gals, and not even a good one at that.