No, he is not referring to the movies, of course he referred to the books. Yeah, both are originated from novels, not an original movie.
Personally I still don't read both books and watch both movies. For movies I still thinks both are crap. Don't like any of those series. And I can't imagine my self watching it in near future.
For books, it is not in my reading list. Not interested either. But it is not total rejection, I might give them a try when I run out of something to read.
Other quotes from Stephen King.
"If you don't have time to read, you don't have the time (or the tools) to write. Simple as that."
"Good books don't give up all their secrets at once."
"Books are the perfect entertainment: no commercials, no batteries, hours of enjoyment for each dollar spent. What I wonder is why everybody doesn't carry a book around for those inevitable dead spots in life."
— Stephen King