Why should they be? I used to jailbreak, but Apple added almost every feature I needed and now it takes JBers 3-6 months to jailbreak the latest iOS, so I don't bother with jailbreak anymore and install iOS 6 the minute it comes out (and profit).
Well, I think it's more reasons than just new features. It's the very idea of escaping the walled garden. You can disable the killswitch, you can install any tweak you please, or even develop your own. You don't even have a filesystem explorer unless you jailbreak, or a console.
The jailbreak tweaks are usually better than Apple's own implementations too, even from the beginning. Backgrounder is far more powerful than built in backgrounding. LockInfo is extensible and beautiful. Winterboard (and originally Summerboard) allow far greater control over theming than Apple allows. A quick settings pane like SBSettings, incredibly useful, and been there for years.
I can't imagine being without a jailbreak. My iPod Touch would be useless to me without.
Sorry if my poor phrasing made you to write this long response :) I almost completely agree with you, and what I wanted to say was "There's no inherent reason why all HN users should be jaibroken. Sure, they should know why it's probably good and how you can jailbreak you iDevice, but it doesn't mean they should all be jailbroken just for the heck of it".
And thanks for reminding (and torturing) me about SBSettings. Actually, that's the only thing I miss terribly from my JB days...
I don't jailbreak/root anymore. If I've hit a point where $device isn't useful to me without fighting against the shipped OS, it's failed me and I'd rather find something more agreeable to my uses.