Executing a good app is really hard, and people who can do it consistently are very rare still. Getting a really cohesive, well-built app done is more than just hiring the most expensive ObjC coders and designers you know.
1) Solve an actual problem.
2) Resemble/enhance something people already enjoy.
Because the article's #1 point is entirely valid and thoroughly unnecessary for popularity. And #2? Well, good luck with all that (no, seriously, that's exactly what you need.)
You say "Of course your app should be useful", yet your post opened with "Chances are, someone has already thought of your app idea". So to me your post communicates, "Since your app is just another knockoff, polish it up real nice and hope for a media/celebrity mention or a front page link on HN/Reddit."
My tendency would be to say, "Of course your app should have a decent UI" but having owned a few Android devices and an iPhone, my experience is that utility trumps all. It's not unusual for very useful apps to exhibit truly shameful user experience. They may have a high utility factor and even have a polished interface, but be terrible to actually use. (We're going to assume through all of this that we're not even talking about minimal bugs or smooth, consistent performance, those should also be a given.)
Plus half of your first point was really your second point -- in essence, "Getting People to Use Your App" boils down to "Figure out a strategy to get popular."
Look, all I'm trying to say is that surely, with your background, you have more insight to offer than "...make your app high quality. Hike up production value. Make it really good."
I think DrawChat is a beautiful example of how all the flows in the app are focused on getting you to share the content, and close the user feedback loop.
Here's a screenshot that illustrates the gravity in the app store:
Apple will frequently feature high quality apps-- they cycle these all the time. This particular app (top tier investors, featured in NYT, WSJ, etc, etc) was featured twice. You can see what happens afterwards.
I believe that apps having a chicken and egg issue should try to break the distribution cycles they put in place. After all, Twitter started booming because Jessica Alba created an account. Although Airbnb did some great hacking, they manage to get 2 minutes on CNN with their Obama corn flakes.
It seems like the simplistic ideas are the ones that go viral the most quickly.
Are there examples of apps that have gotten adoption through ads?