What was so embarrassing about Extinction?
According to Memory Alpha, both LeVar Burton (who directed the episode) and Brannon Braga (one of the producers) were embarrassed by this episode. Braga reputedly said it was one of the worst episodes of Star Trek, period, that he had been involved in.
What was so bad about this one episode? I rather thought it was pretty good.
If there's anything to be embarrassed about int he Trek universe, it's the fact that nobody ever thought to simply shut off Data every time he started rambling on about inconsequential trivia (or at least incorporate something into the show whereby he actually learns that people tend to find such ramblings tedious).