Can a Novelist Be Too Productive?

I love Stephen King's writings. He is one of my favorite authors along with a few other exceptional writers. When I was a teenager, his novels and stories that I'd read, had profound effect on my love for contemporary English literature. Whenever time is available in these days of dwindling time in the middle of workday and family life, I still pick up his latest novels. To me Stephen King's prolific output is not shallow contribution to the world of literature.

His latest article on New York Times points out some snobbish ideas that some holds in the upper echelon of literary world that writing too many novels and stories diminishes a writer's worthiness as a great writer. In some cases this claim is true but as Stephen King states, "No one in his or her right mind would argue that quantity guarantees quality, but to suggest that quantity never produces quality strikes me as snobbish, inane and demonstrably untrue."

Here are some profound observations from Stephen King:
"I understand that each one of us works at a different speed, and has a slightly different process. I understand that these writers are painstaking, wanting each sentence — each word — to carry weight (or, to borrow the title of one of Jonathan Franzen’s finest novels, to have strong motion). I know it’s not laziness, but respect for the work, and I understand from my own work that haste makes waste. 
But I also understand that life is short, and that in the end, none of us is prolific. The creative spark dims, and then death puts it out. William Shakespeare, for instance, hasn’t produced a new play for 400 years. That, my friends, is a long dry spell."

Reference: Stephen King: Can a Novelist Be Too Productive?