Done properly (ie keeping within manufacturers 'max safe' VID and temp ranges) - Overclocking is not the big bad hardware killing boogey man.
Obviously Overclocking has the potential to shorten some components lifespans, depending on how far it's pushed, build quality etc - but reading, researching and double-checking goes a long way in potentially alleviating most 'expensive mistakes'.
As to whether or not you need to is entirely an individual choice.
Right hardware + research/knowledge = is worth the performance gains.
Going in balls deep without researching first = Not worth it. Same applies for simple 'bragging rights'.
I certainly can't disagree with your points, but I do believe that it isn't always worth it. There are good and bad reasons to overclock, because in some cases, the real world performance gain is small, and the potential for an expensive mistake is always there.
OCing should really only be tried if you know your hardware well, and do your research beforehand. With today's speeds on CPUs, most humans probably wouldn't notice the speed improvement. My stock speed is 3.2 GHz, and I OC to 3.8. It's a Black Edition Phenom, and I bought it for that reason, so why not? I can also afford to replace it, and I know when to stop.
The reason that I try to discourage wanna-be OC'ers isn't that I want to keep them from doing it. I just want them to read what I say, and maybe think "Okay, maybe it isn't so easy. I'd better read up on this." I want them to do it carefully.
I've been doing electronics for over 25 years, and IMHO, I pretty much know what you can and can't do with electronic equipment. There's nothing wrong with OCing, if you do it carefully. I hang out on an OC forum, and almost everyday there's a post from someone who has flamed out his CPU, or MOSFETS, or some other critical component. I hate to see that happen, because almost everyone there says "Take it slow and easy.", including me.
I don't want to discourage people, I want to encourage them to do it right.