You do know Seven was brought onto the show to boost ratings? The same for when TPTB brought Worf to DS9...for all the good it did to either series, since the ratings spiked for half a season before declining again.
In any case, I still stand by what I said earlier. The assumption of seven seasons hurt this show badly, and especially coming off the heels of Voyager.
Yes, I've heard they were brought on to boost ratings; as far as I know, every show is concerned with keeping or boosting ratings.
Worf and Seven are two of the most popular and iconic Trek figures; it would have been a shame for fans to miss their continuing appearances.
I'm grateful for all the Trek that makes it to the screen, even my less favorite ones. The ones I don't like, some other fans do; and that is only good for the world of Star Trek.