This is like saying a critic excels in the field at which they criticize.
Last I checked Ebert only had terrible films in his history, the Louvre wasn't hanging many paintings by renowned art critics, and Yahtzee's games were largely only "okay" from a gameplay perspective.
It's easy to point out how the other guy fucked up (especially when you have a team of writers). It's not easy to do a good job yourself.