Katt's not so much condescending as he is senile. He just keeps blathering on about absolutely nothing and Costas always cuts him off with "indeed" or "very interesting, Jim!", which is amusing.
f***, he was never a good *hitter* either. His sole use was getting on-base, and this season he's been doing a shitload of hacking and has a pathetic OBP, so he's literally a waste of a roster spot.