Because today, 20 % of Israel's population is Arab, whereas there are virtually no Jews left in any of the Arab countries. The fact that Mizrachi Jews were Zionists and that they didnt few themselves as refugees (because they viewed themselves as coming home) doesn't contradict the facts stated in the article that they left because Jewish life had become too dangerous to stay where they were. In countries where aliya is really voluntary like the US, France, Briton etc, large Jewish communities remain, and even in countries that have been dangerous like Argentina, large Jewish communities remain. And you, by the way are ignoring the hundred thousand or so Palestinians who left prior to the termination of the Mandate - at a point where they could not have been forced to leave.
Middle East quartet reportedly set to meet during UN General Assembly (dpa)
from the article: Comment / Settlers can stay, but only as citizens of Palestine