The author is spouting mostly nonsense and his points are ignorant or disingenuous at best. The whole article is aimed at why developers should develop for BB10 rather than WP8.
1. Large user base to present BB10 to.
He author argues that it's better to develop for BB10 rather than WP8 because Blackberry has a user base of 80M. SO WHAT? Apps made for BB10 are NOT compatible for anything before it. That means the audience for BB10 apps as of now is..... drumrolll please...... 0.
2. Stronger market presence
The author argues RIM has a larger presence in the mobile arena than MS, 5.2% to 3.6%. Again.... SO WHAT? What percent of either of them are going to be in the market for either BB10 or WP8 apps? For BB10 right now, it's 0%. For WP8, it's hard to tell right now. What's important is not legacy market share for developers, it's the market share going forward. That, is not easy to predict.
3. RIM takes a different approach from Microsoft on platform transition
The author argues that MS has only just started the transition to mobile after abandoning for years. Again, SO WHAT? Both are new platforms. If the argument is for customer loyalty to a brand, then I could buy it. Also, MS's platform transition was started 2 years ago. Sure WP8 is not compatible with WP7, but the look and feel of WP7 and WP8 is identical. The transition from BB7 to BB10 is going to unrecognizable.
Basically, at this point in time, it's hard to say who's better to develop for. If you're a big player, then it's obvious you're going to pick MS, simply because they are offering huge incentives. If you're a one man shop, then it's a flip of the coin. There's also one other thing to consider. If WinRT picks up any traction, there could serious incentives to develop for WP8, simply because it would be a very easy transition. Make one app, sell it on 2 platforms. That's one of the reasons, aside from the huge audience, iOS has such a large developer base.