@culi If you are ranking them, I don't see what added benefit separating them into two lists makes.
Approval voting does indeed force you to make this binary choice. For simplicity's sake, you can word it "those you want and those you don't want", but a sophisticated voter probably won't (or shouldn't) see it that way, since the real world is neither so binary nor so absolute.
For me, "approve" might mean "who do I think is better than who I think is most likely to win?" or something like that. Which unfortunately burdens me with trying to keep track of polls or otherwise estimate who is likely to win.
That is still a binary, of course -- if the election is approval, you have no choice but to see it as a binary. But you don't need to see it as an absolute measure of "want" vs "not want", but instead can see it as relative to other candidates (typically seeing candidates that seem to have little chance of winning as being less relevant to your decision).
The point is, once you've ranked the candidates, you have given all the information needed. Deciding where the "approval threshold" should be provides no meaningful additional information, and simply adds a burden to voters -- guessing who will be front runners -- when they really shouldn't have to worry about that.
In case the above isn't clear enough, here is an example. Say there are ten candidates, A-J. I might rank them as follows:
C>H>F>B>E>J>I>D>G>A
Now you ask me to split that into two lists, for instance:
Approve:
C>H>F>B>E
Disapprove:
J>I>D>G>A
Assuming I am a sophisticated voter that is thinking about strategy, there is one and only one reason for deciding to split the lists between E and J: my estimate at the chances of various candidates to win. For instance if I think E and J will likely be the front runners, that would be a natural place to split the lists.
But that has nothing to do with my preferences, only my predictive skills. And I can't see why anyone would want that to be a factor.
