With the Golan Heights under its control, Syria will be able to resume shelling northern Israel and Israel will lose the ability to monitor and detect potentially hostile Syrian army troop movements.
Giving up the Golan Heights is risky. Israel can not afford to take that risk.

The argument that the Golan Heights are strategically valuable to Israel may have been true in the 1950s and 1960s. Syria then dominated the Heights and was, with its short range artillery, in a position to threaten Israeli targets below.
With the advance of technology, however, that argument is no longer plausible: Syria has long range surface-to-surface missiles that, if launched from anywhere in Syria, can hit targets anywhere in Israel — with or without the Golan.
Satellites! … why would Israel need the Golan?
Israel has a higher mountain than the Golan Heights and can see all of Syria. Therefore, the above argument should not be on the table at all … just like Syria should not be asking Israel not to use its satellites’ advantage over Syria.