The interpretation you have of stealth usually comes from the following rules snippets from the stealth description:
Being Observed: If people are observing you using any of their senses (but typically sight), you can't use Stealth. Against most creatures, finding cover or concealment allows you to use Stealth. If your observers are momentarily distracted (such as by a Bluff check), you can attempt to use Stealth. While the others turn their attention from you, you can attempt a Stealth check if you can get to an unobserved place of some kind. This check, however, is made at a –10 penalty because you have to move fast.
Breaking Stealth When you start your turn using Stealth, you can leave cover or concealment and remain unobserved as long as you succeed at a Stealth check and end your turn in cover or concealment. Your Stealth immediately ends after you make an attack roll, whether or not the attack is successful (except when sniping as noted below).
In actuality your interpretation is overly harsh. As you can see from the quoted material you do not lose stealth automatically by virtue of not being in cover. Rather, you cannot start stealth while observed, and you are considered sufficiently unobserved while in cover. Exceptionally, you may take some actions that would normally break stealth or apply large negative stealth penalties and still remain hidden if you start and end your turn in cover/concealment and make a stealth check. You can also become sufficiently unobserved via other methods, which the archetype you mention is addressing. You break stealth when you a) fail a stealth check in a situation where you could be observed, b) run, attack, or charge, or c) decide to stop using stealth.
One of the ways to hide while observed is to distract observers via a Bluff check. This is a Standard Action, normally. The archetype changes it to a move action, allowing you to (each round) Standard Action attack, Move Action Bluff, Not-an-Action Stealth, Free Action 5ft step, which you could otherwise not do. It is entirely obsoleted by Hide in Plain Sight, within the latter's terrain type, but serves a similar purpose.