iss you are completely and totally wrong.
Perhaps in the higher end of the spectrum, especially that people go all-out for cooling and then spend 6 hours a day surfing the net, yes, overclocking has no real purpose.
However, for someone like me, who cannot afford the newest hardware OR would like to push their hardware to the limit, overclocking has very practical use.
Example.
I wanted to have a computer that I would have to watch DIVX movies on. I didn't have any pentium 2 class cpu or board at the time (celeronA+, p2, p3), all I had was a k6 box. It was clocked at 400mhz and could not play movies reliably without skipping/pausing. Now I could have either forked over the cash for a new rig that could play movies reliably, or possibly even piece one together for only $100 or so total (board, cpu, ram, etc).
However, instead, I overclocked.
Rather then spend an obscene amount of money on cooling though, I simply modified the existing one by sanding it down, getting a cheap (cheap) thermal goop tube, putting a $4 fan to exhaust air from the case, and brought the cpu up to 522mhz. I made a few other changes as well, a slight FSB overclock, a few memory tweaks.
Viola, I could watch all the movies I wanted at full speed without skipping or the audio getting out of sync.
Total cost? $11. Total gain? Extended the life of the system by another year rather then having to purchase a new one.
Another example.
I do a lot of compiling. I ended up installing gentoo on my p3 several times, from base (stage1, I never use precompiled binaries and I always bootstrap). Originally it took around 4 hours to do bootstrap, build system, compile kernel. This normally wouldn't be too bad except that i was doing it so often. Then, when I started to get into things like compiling KDE3, it would take OBSCENELY long - 9 hours sometimes. It was taking way too much time.
But again, I couldn't afford to buy a newer system.
So, with a very simply case mod that cost me only the time to do it, I then took that box from 100mhz FSB to 120mhz FSB, from 1ghz p3 to 1200mhz.
I shaved almost an hour off the time it took for base install, and MORE then 3 hours of time off of the KDE compile.
That was just one of many applications.
And yet another example.
I used to be a lot heavier into gaming.. recently not as much. However, I was having difficult achieving a constant framerate in UT. At certain points it would dip low - way too low - low as 10fps. I couldn't live with that if I was playing a very fast-paced game over the net. I couldn't afford a better video card, but with some software tweaks, a CPU overclock of about +10%,, then an overclock of the video card memory core, I never saw 10fps again, it was now dipping to maybe 25fps or 30.
Months, even years later, all those systems are still healthy and still functioning.
Don't ever for one minute tell me overclocking has no purpose, no point. Sure, maybe with the highest end systems we don't currently have a need for massive OC, but as more demanding software is released, I will be spending the time modifiying my own system with things I can do at minimal cost, rather then forking over more and more money to get the "biggest and best".
. 
