It's a good article and a belief that took me 23 years to figure out. In my experience, all my lead-ins, excessive or not, have really garnered most of my rejections. Although you do not have to start mid-action (it really does help), you can start mid-conflict with a scene or dialogue. Start with a problem or baffling question right from the get, and it's not necessary to fill the reader in on why or what's happening. Less is better--hook--intrigue-confuse, confound--whatever it takes to draw the reader in.
Anytime one of my partials comes back the the comment, "I just couldn't get into it," I know I've failed.
There are some stories that do require some type of setup but, again, make it brief and get on with it. I don't need to impress you with my fabulous prose, the weather, the geography/location, character background etc,. I have to impel you to click or flip to the next page. Once I've got you, I'll fill in by sprinkling a little bit of info here and there, but I won't apologize by explanation or any back-story. The reader is a lot smarter than you think and they can do a great job of filling in the blanks. And even if they do get it wrong, it's a moment of discovery or a WTH moment.
Keep 'em guessing.