He says "vehicle for gravy" like it's a bad thing.
Turkey is the platform for all those side dishes, the bass-line of the song. Also, it looks really good on the platter.
We've been frying turkey for years, in part because it's fun; you can do other good stuff with the oil, too. My sister cooks a breast in the oven, too, so the stuffing will have flavor and because some people like tradition.