"I can't help but wonder if TV, by chasing narrowcasting down the new-media rabbit hole, is stratifying itself into creative limbo," he wrote.
Where that might lead is anyone's guess.
Already, Peter Chernin, the former president of Fox's parent, News Corporation, has announced that his production company is introducing a reality series that will run solely on Twitter and other social media sites. That follows in the wake of some scripted-improvisational shows, such as "Childrens Hospital" and "Web Therapy," that began as online shorts and then moved to television networks.
Indeed, not only are there are more outlets than ever -- there are more devoted fans to support their darlings.
The long-canceled "Veronica Mars" maintained enough of a following for fans to pitch in $5.7 million on Kickstarter to launch a movie; "Arrested Development" comes to Netflix at the end of May, partly because the show never really went away. (Thanks to DVDs and streaming services, you never have to stop watching your favorite show.)
At least, all these programs will provide critics such as Sepinwall plenty to chew over.
"TV is aspiring to more complexity now than it ever has before, and that in turn makes it easier to write about it the way that I do," he says.
Besides, he says, now he knows he's not alone when his DVR runneth over.
"Both from TV critics and non-TV critics alike, it's been, 'Thank you!' " he says with a laugh. "'If you of all people are saying it, then I'm not going crazy here.'"
HBO, TBS, Turner Classic Movies and The CW (formerly The WB) are units of Time Warner, as is CNN.