A few spelling mistakes corrected 
I don't think you can say point blank all drivers on the current F1 grid couldn't hack it back in the day. Just because they don't have to doesnt mean they couldn't. It also works the other way round.
It's clear that all great champions have one thing in common and that's a sheer determination to win. Put (dare I say) Hamilton into a 60's F1 car and sure, he would have the fright of his life. But I'm sure he would become familiar with the car and would end up very quick.
On the flip side, put Clark into a modern F1 car and he wouldn't last 3 laps initially. But I'm sure he would adopt the rigorous and specific training regime needed to drive these cars quickly, and again would be up to speed in no time.
You can't argue either side conclusively. The game has changed. The skill set required to suceed has changed and drivers who are winning today may not have been able to win 30 years ago, and vice versa.
The only type of comparison I can think of is TT (or any road racing) vs moto GP. Now, I view the technically most gifted riders to be the moto gp front runners. But put one of those riders in a TT race and they wouldn't feature initially, due to the different skill set required I.e. ultimate bravery and pushing the boundaries of grip vs the desire to keep living. But take away all other modern forms of racing bikes, then some of these moto GP riders would race the TT, and after a few years, would get up to speed and become front runners.
As for the 'playstation' f1 cars of today, I would like to see anyone of you dismissing them as such taking Eau Rouge or Becketts/Maggots at racing speed in one. I doubt it's any where near as easy as it looks. And Kubica's crash at Montreal, or Kimi's off at Monza, or the first corner incident at Spa last year look like no PS3 game I would like to be playing. These guys are still taking very big risks.