Oh but your grace, I might argue with that...
I've built a media centre pc for my front room, it goes like this: 5.1 speakers - one in each corner, high up above the picture rails and the bass bin hidden behind the lcd tv, windows vista home premium with 850gb storage across two hdds, xfx geforce 6600 gpu, creative audigy 2 and pentium 4 3ghz plus.... wait for it, Dvico dual dvbt freeview tuner and all told, it rocks. I can sit in my front room with my ms green button remote and have tv, music, pictures, video and dvds all at the touch of a button.
Particularly with tv, the tuners work great and the media centre guide is fantastic - although I have defended vista on here and may appear an ms apologist, I'm not - I do think ms get lots of it very, very wrong, a lot of the time - but I do think that media centre, when shown off to it's true capabilities is the killer application of the century so far and absolutely made for pc tv cards.