A baby's whining? Perhaps you should read what I put instead of seeing I disagree with you and starting with the name calling. I'm not in anyway suggesting that a people with their own culture and nation are my people - if they were I'd be coring and culture converting them rather than setting them up as a vassal. In the example, (released) Scotland is now again a nation, but it is a vassal, paying taxes to me in return for my protection, in a fairly traditional agreement between liege and vassal; they're not my people, they're foreign, but tolerated as a subservient and hopefully reliable ally who pays me for the privilege.
The concept of a released vassal state and a client state are different. With a vassal (especially a released one), you are indicating that you still consider the previously existing entity to be valid, but now they work for you as well as their selves. With a client state you've drawn a new country on the map, given it a flag and a name and gone "this is now a country" and relying on being powerful to have people accept it.
And, in a shocking piece of news to you : client states are only possible later in the game, whereas vassals are how you deal with defeated but unabsorbed land earlier on in the game. Releasing an otherwise ungovernable land mass as a vassal is a valid and sensible tactic, since you can install a puppet of some sort (governor, duke, despot, viceroy, call it what you will) to run the country and send you some of the profits. Client states are also only available with the Art of War DLC.
Now, a vassal can turn on you - and so it should be able to - if it decides it doesn't like you anymore, or it becomes sufficiently powerful, either alone, or in concert with your other vassals, and they have a penalty that keeping them annexed doesn't - they eat up a diplomacy slot.
As for Paradox not having thought of my idea, I thought the idea was to debate and discuss ideas, so that Paradox can see how the userbase is interested, especially with a feature they're obviously looking at changing slightly. As such, I find your name calling and attitude towards people who hold a different point of view a little disrespectful, and wish that you'd discuss it properly, actually reading what I have written rather than what you think I'm writing.