Yeah, sinkerballers are no bueno. I saw Nova getting absolutely crushed on sinkers in the bottom of the strike zone. Sinkers=Bad.
I believe they're 5-10 years behind the rest of baseball in their analytics dept. Don Cooper is a relic. He used to be a great pitching coach, but by 2012ish the game had passed him by.
Giolito is a great example, He had a ++ curve when he got here, and Cooper taught him a slider. Now his slider is still a pretty good pitch, but with the way he pitches, his high fastball that he throws by hitters would be better paired with a curve than a slider. Giolito has completely lost the feel for his curveball since learning the slider.