Scay, you're not even remotely close to being right.
First off, your analogy is completely worthless. Floppy drives are mechanical objects with moving parts, as are hard drives, which means that even if you did have software that could "destroy a hard drive within hours" (which I doubt), it still has no bearing on this discussion.
Processors are absolutely designed to run at full load for extended periods of time. What the hell did you think "Prime95/Furmark stable" meant? Many good builders, and all competent overclockers will run these programs for hours before considering a machine stable. On my machine, neither the GPU nor CPU reach unsafe temperatures under full load, topping out at 75C and 48C respectively (though the GPU usually doesn't pass 60C), and running them for hours, days, or even weeks would be no issue. Indeed, both are run intensively for hours a day as it is. Neither have aftermarket cooling, both are overclocked, and both do what you claim hardware can't do. So much for that theory.
Your examples of what would "damage" a card also have relatively little to do with reality. Having a card produce a mere 100fps in a 3d application is hardly a damaging activity. Again, my cards do it for hours a day, and before you make comments on the life of my hardware, my Radeon X850PRO from 2004 is still running without a hitch (now in a hand-me-down machine), and it's by far the worst cooled component I've ever owned due to its single-slot cooler.