Roger Ebert rules

Why is Roger Ebert considered the greatest living film critic? Sentences like this:

I was surprised how much I laughed during "Juno," and then surprised how much I cared, especially during a luminous scene when the woman who will adopt her baby (Jennifer Garner) solemnly places her hand on Juno's pregnant belly and the two exchange a look so beautiful that if I'd known it was coming I don't know if I could have looked.