Yes, the blogger is Jewish. But it is no more a Jewish-run blog than Live and Let Fly or One Mile At A Time are Christian-run blogs. It may seem a minor distinction, but calling something a "[insert religion]-run blog" implies that it is controlled by a certain religious organization, which in the case of the Jews is an old and tired trope.

I don't get the sense that you were trying to communicate anything other than surprise at learning something new, and I am not trying to drag you in any way, but language matters.