Why have some Sahrawis become Moroccan citizens while others ended up in refugee camps?

Quoting from this article,

The Sahrawis who did not flee have been given Moroccan citizenship.

Is this all there is to the story? Much of the literature on the Western Sahara conflict overlooks why some of the native Sahrawi ended up in Tinduf while others remained. Were the former expressly chased by the Moroccan forces, and if so, what distinguished them from their fellow Sahrawis who did integrate the Moroccan realm?

In other words, to what extent are the Sahrawis in Tinduf "self-exiled" (e.g., for ideological reasons) as opposed to forcibly exiled (e.g., via the exactions of the Moroccan army)?

EDIT:

To better qualify the question, what evidence do we have that those who ended up in Tinduf were expressly chased by the Moroccans, as opposed to co-opted into leaving because of ideological factors (from within the Polisario elite, from Algeria, Spain, etc.) The very definition of "refugee" as opposed to "self-exile" rests on whether the move was from their own volition. This is all the more paradoxical in that significant numbers of them remained in (what is now) Morocco and willingly integrated its institutions (political, educational, etc.).