Why am is it that the legionares hate me yet they wont attack me? I can walk into there camps and they tell me they want to kill me but don't do anything.

What's your reputaion with that faction?
If neutral they should stay non hostile apart from dialogue.

You have a good enough rep with them for them NOT to kill you. In other words: The brass don't like you but you pull off crap that they can't thus you live

But I'm vilified by them, they hate me.

Are you sure that you are still Vilified?

Do you carry

Are you wearing faction clothing?

Even if you have a middling to good reputation with them, they still regard you as sub-human.

Yes, I'm vilified.

No, I'm not wearing faction clothing.

No, I'm not wearing or carrying [spoiler].

I have some legion armour in my inventory but not on.

Any suggestions?

Its a bug, sometimes Vilification wont have any effect until you reach the Strip and get your rep slate cleaned, then, if you regain Vilification, they will attack

I don't think it's a bug tbh, as this happens with the NCR too.
I started off PO the legion on this build, still getting the assassins and ranger parties also hostile at the right time.
Those camps I've found of cl before Novac however are still neutral untill attacked first.

I think this may be a satety net to stop you accidently ruining the choices later on untill after the strip.