Why not?
Because a Beta's lifespan is usually only several weeks before a new version releases. The security hole will more than likely get plugged with each beta.
If anyone bothered to read, the jb doesn't use any new exploit. It's the same as before.
You can jb, but you MUST boot tethered. SSH Works so you can install Cydia manually (They claim Cydia is broken but it actually worked just fine for me, most likely just a BS claim so there isn't a rush on it). I wouldn't try it yet. I had apps disappear and reappear all kinds of weirdness. I'd wait.
Do they need a new exploit to do an untethered? That would be a waste of an exploit. If not, it's probably just because it's not worth it for a developers beta that doesn't have that many people using it in the first place.
They probably do. That's why the beta JB is a TETHERED JB. They're playing it safe and not burning any exploits. These betas are for devs to test their jb tweaks basically.
That makes sense. I'm glad the hackers are being smart about how they "use" or "burn" the exploits. Hopefully that will enable them to keep bringing Jailbreaks. I'm hoping for one shortly after 6 comes out, as I committed to keeping my 4S, but I want to be able to put iOS 6 on and keep MiWi and such.
Yeah, they said the one pod2g developed for 5.1.1 will partially work on 6.0 so hopefully they wont take as long to get one out for 6.0. I LOVE my Springtomize!
Because a Beta's lifespan is usually only several weeks before a new version releases. The security hole will more than likely get plugged with each beta.
If you have an A4 device you can do a tethered jailbreak, though they say it doesn't include cydia, you can get it by following this guide
http://www.idownloadblog.com/2012/06/18/how-to-install-cydia-on-ios-6-beta/
Keep in mind, not all tweaks are updated for ios 6, so use at your own discretion.
Don't know why people down voted you, having a jailbreak is the single reason I don't criticsize apple's updates, because if the public can't do it and release it in cydia, I have no reason to expect it from apple, and if the public can do it, then I just download it. I enjoyed wifi syncing a year before iOS 5. Win win.
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A4 devices have a hardware level security exploit, called limera1n or something. There will always be a tethered jailbreak for A4 devices.