Knowledge isn't dangerous... if anything, it's ignorance that should be feared.
I mean, what if you were to take something prone to security holes - an internet browser. And make it available to everyone! Anyone could find and see the vulnerabilities, and a community of people would be dedicated to
teaching others about those vulnerabilities. How awful! How horrible! How... Secure. Welcome to Firefox and the future of open source. Using Internet Explorer is like asking for malware.
Same thing goes for operating systems. Ever hear of Linux?
Everything is going to have some vulnerability, some security hole. And it's only a matter of time before someone finds it. So honestly, which would you rather have? Thousands of people (well, hundreds of thousands actually) knowing about the exploits, or just a handful who are really determined?
Keep in mind, 99% of people who are exploiting these security holes are harmless or beneficial, helping to make new applications or just supporting new programs. Only a tiny, tiny minority would actually attempt to cause damage with these by creating viruses, etc. And this minority can be very, very determined.
So by "teaching thousands of people how to exploit security holes in the iPhone," you actually guarantee a greater level of security, because the security holes aren't just secrets used by people to create a virus - they're used by many people to help the user, and to make more out of the product they bought.
As for your sarcastic "Yeah, no impact on anyone!"... I couldn't agree more. It has a huge impact on many people - like me, who get much more use out of their phone now.

I paid 600 bucks for it (Yeah, I was one of
those fools), why shouldn't I get to use it however I want? I'm not holding Apple responsible if I break it. Their warrantee doesn't cover this, and that's understandable. I just want to use it how I want, and I'll be responsible for that.
This comes from someone who has attended the largest hacker conference in the world (Defcon) - which is full of nice people who share an interest of making things work better, in more ways than originally intended or limited to.
Edit: Erm... Just remember that if you go to Defcon, that 1% really starts to add up when you have a few thousand people... Better keep wifi off.