We play this game in English.
It is a game, even if the players confuse it with reality.
It's to use a plural without the article in two different ways.
"Palestinian artists and intellectuals" do something. We think it has to mean "the vast majority" or "all". But there's another reading under which it merely means "some"--as long as it's plural, it's okay to use it.
We play this game in US politics, too. "Economists claim ..." but then it turns out that one school of economists, government economists, some private economists, etc., do the claiming--not all, not even most. Or scientists. Or researchers. Or scholars. Or doctors. Or whatever is convenient to bolster our case. We know that it's going to be interpreted one way; but we can always defend the words, if not the intended interpretation, by recourse to the second meaning. These are usually not just a partial representation, but also embedded in an appeal to authority. It wins over those who are won over and makes them feel much more superior than they did. Doesn't change much else, though.
In other words, good for rhetoric; not much use for understanding.
Self-identification is also messy on the ground, and malleable. Easy to prime people to get the answer you want. Ask an apparently unrelated question and you set them up to give a certain kind of answer later in the survey.