Sure, driver skill is always a factor. But here's the thing. A torsion bar suspended, leaf spring equipped, 4 door B body came in 2nd place. That car has a 116" wheelbase. Think about that. It averaged over a second faster a lap than a coilover equipped, 4 linked A-body with a 108" wheelbase. A full second. On an autoX course. We aren't talking a mile long course. 1 second in a course that's being run in 48 to 54 seconds.
And really, read that article. Take a look at the suspension set ups on some of those other cars. Look at those cars! These aren't grocery getters, most of them are purpose built track day machines. And we aren't pulling drivers off the street, most of those drivers frequent track events. All those cars have a minimum of several thousand dollars into suspension set up. Heck most of them probably have $10k in suspension work. Maybe more. And they were slower than torsion bar/leaf spring car.
Yeah, the driver is always part of it. But so is physics, and a 4 door 116" wheelbase car has some serious disadvantages in the physics department. And yet it still managed to be faster than a whole handful of cars with some really fancy suspension. I mean, fully subframed Camaro's vs a '70 Satellite 4 door? I'm not saying that coilover set ups can't be fast. They can. But you don't need them. And it doesn't have to be just the Hot Rod article. Look at what Tomswheels did with his Valiant in the CAM class. I mean, 2nd only to Mary Pozzi at SCCA San Diego? Not bad considering Tom's '67 Valiant was probably giving up 250+ horsepower to Mary's '73 Camaro.
The point is torsion bar cars can be fast too. Faster, in fact, in the right hands.