Who knows, maybe there was a time when that was even valid, back when TV was a kind of cultural wasteland, but without a doubt it no longer is. I honestly think if you want to see the best dramatic writing going on right now you are more likely to find it on TV than in a movie theatre or on a stage.
In the last few years we've seen, The Sopranos, The Wire, Battlestar Galactica, Mad Men, Fringe, Breaking Bad, Lost, Terriers. On the comedy side there's 30 Rock, Community, Parks and Recreation, The Sarah Silverman Show, Arrested Development, Modern Family.
This is just off the top of my head, but the point is this--there is, and has been for awhile, some really great stuff out there. Work that is ambitious and detailed and superbly well written.
How did this come to be? Why so much quality TV now? I think the biggest reason is because of the huge segmentation of the viewing audience. With hundreds of niche channels on cable plus the internet, we have more choices now than ever. People who produce TV shows are scrambling for our attention and to do that they're more likely to try something a little off the beaten path. Gritty dramas will get a shot as will darker and more absurd comedies. They might not all last but they at least might get a shot. And because it's understood that viewing audiences are smaller now a show can survive on ratings that would have killed a show ten or fifteen years ago. So let's kill those culture snobs dead people! Let's talk TV with abandon! What are you guys watching and loving? What am I missing?