No, that’s not what I take from that advice at all. For me it’s the qoute from Stephen King “if you don’t make time to read then you’ll never make time to write” something to that effect, I paraphrase. To me it makes sense not because they want us to buy more of their books, but because the two kind of go hand in hand. Read more, soak up loads of different texts you will willingly or unwillingly learn from what you read. The concentration and the dedication to reading is tantamount to being able to sit and write. It requires imagination, interpretation and its something we all take for granted and seldom people make the time for.