I really have to disagree. As authors we need to write the best books we can.
Of course we do. But it's a lousy keymaker who creates a key without considering the lock first.
That wasn't the point of my quote, though. After you write a book, and you're promoting it, there are different catagories of buyers. For example, when I speak at a mystery bookstore, it's a much different crowd than speaking at a literary festival.
Book readers fit into catagories. Die hard buyers, who read everything. Casual readers, who read a few books a year on vacation. Gift buyers. Johnny-come-latelys. Booksellers. People who never go into bookstores. These are all groups to target, and all should be approached in different ways.
Any other marketing we do is invisible if the publisher isn't already doing its job. As far as running around to bookstores takes time and energy away from writing, it's counterproductive.
Your publisher is your business partner, not your boss. You're both responsibly for marketing.
You can write a great book, with great distibution and a decent marketing campaign, and it can still slip through the cracks. The more people you reach to tell about the book, the better off you are. And it's possible to reach a lot of people on your own.
No one mentioned marketing at the expense of writing. Marketing is what happens after you've written a great book.
The more promotion you do, the more books you'll sell, the more you'll strengthen your brand. You can have a zillion legitimate reasons not to do any sort of promotion. Numbers don't care about your reasons. Neither do publishers when they're looking to buy books.