Even without reading the article I can answer this.
C and C++ are closer to machine-language than other languages. As such you have great control over what you can do in them.
The language is universal so what you write in C or C++ can easily be ported to other computers, including cel-phones and other game platforms, including Playstation 3 and Game Cube.
With direct control also comes speed. C and C++ are going to run faster than most other game-programming languages for the very fact they are closer to the 'root' of what makes your computer tick.
But with all this power also comes complexity and what I call, "barity" or bareness.
It is a lot harder to build a simple program in C or C++ to do the classic text on the screen, "Hello World" than, for instance B4GL or Q-Basic, and to maintain a universal compatibility.
C++ is a developmental language designed for creating massive complex systems and programs. Like it or lump it, languages like B4GL, Blitz-Max, Q-Basic, and Thin-Basic are all equipped with training wheels and it's kinna hard to take them off.
You will always be limited using these simpler languages, but that's the price you pay, ease-of-use and simplicity versus speed-of-execution and versatility.
As for me, I have never considered myself an adept programmer so I will always choose a training-wheel language over speed, like B4GL and Blitz-Max, although I will certainly try and find ways of 'tweaking' a language to get 'the-quick-and-dirty' done as well as and as quickly as I can without ever really entirely trying to understand the process behind it.
Reading the article you provided, however, I did not know there was a considerable speed difference ! Even today C is faster. Strange, you would think they would be equal with all things considered.
If you're curious, I actually used to know quite a bit about C++ and programed it on the Commodore Amiga 1000 years ago. It was a real pain to work in. Fortunately someone came out with a Fast-Basic and called it F-Basic and I got all the updates for it.
Unfortunately F-Basic had one bizarre limitation, you could only have 20-images 'saved' in your arrays at one time, making for a rather complex written RPG I wrote in it later called, "Dragonhunt" that had original music I wrote in SONIX.
And the Commodore Amiga, if you wanted maximum colors required you to use a 320x200 pixel mode with no more than 32-colors (which you could palette and animate). Yeah, those were the days - glad they're gone. I LOVE the 64-million color possibilities on pc-today !