If there exists a sensical answer (i.e. not a variation on "because that's the way it is"), it's related to not receiving the advertising with the torrent. You seem to be under the mistaken impression that the show is the product. Unfortunately, just like in any other advertising-driven area, you are the product, and the show is a means to get your eyeballs on the advertising.
(Just to be clear and attempt to curb as many silly replies as possible: Just because it's true doesn't mean that I think it should be. Furthermore, your contrived circumstances wherein you turn the TV on and off at just the right moment to avoid seeing the ads is of no interest to me; besides being basically impossible to do properly, even most people doing other things during the commercials will be exposed to the advertising in some fashion.)
(Just to be clear and attempt to curb as many silly replies as possible: Just because it's true doesn't mean that I think it should be. Furthermore, your contrived circumstances wherein you turn the TV on and off at just the right moment to avoid seeing the ads is of no interest to me; besides being basically impossible to do properly, even most people doing other things during the commercials will be exposed to the advertising in some fashion.)