You have to accept that wars can change borders. After WW2 Russia acquired part of Poland and Poland in turn acquire part of Germany. No one is suggesting the previous borders should be restored.
The article indicates that Israel is occupying ten per cent of Syria. This is false, do the math. The true figure is less than 0.62% (440 out of 71,479 square miles). The reason Israel does not relinquish the Golan Heights is in the name. It cannot afford to have Syrian guns once more firing down into Israel in the valley below.
As the Syrians cannot be trusted not to make war on each other, why should Israel jeopardize its security by handing over this territory. At least one policy unites the factions in Syria-they all hate Israel.