There is one major factor no one ever brought up. You purchase pre overclocked hardware it does not void the warranty. You purchase a vanilla card and over clock it yourself, you void the warranty. Also, even though you are correct with things like firmware flashes and riva tuner, it is very easy to over clock your video card. However, I have seen a lot of video cards go bad a lot quicker because it puts more stress on them.
Cards which are designed to be over clocked tend to have better electronic components on them. My friend had a vanilla 6800 that he over clocked to just under a 6800 GT because they are physically the same card, but after about 1.5 years of use it dies on him at times and gives artifacting. So, its a risk you have to take.
which kind of all goes back to my philosophy is that over clocking is dumb and really is not needed.
Theres a huge difference between overclocking and unlocking. Unlocking extra units or pipelines on your card by flashing it with another BIOS is how you can screw things up, and void your warranty.
If you just use a Windows-based overclocking utility to raise the speed of the Core and memory, the worst thing that will happen is that it will crash, causing your PC to restart. Then all you need to do is lower the speed. And also, if you do somehow damage it this way, theres no evidence of it on the card, so you should still be able to RMA it.
As i said before, the only way to actually damage a card is by overvolting it, flashing it, or unlocking it.
And about your philosophy, I can see that if your from the business world you want devices to be as stable as possible, and last as long as possible. However for gamers, overclocking is the best thing to happen to computing.
Heres an example. Say you want an 8800 Ultra but cant afford it, so you buy an 8800GTX and overclock it. Now you have an 8800 Ultra for the price of a GTX.