Bibi insists that Gilo is safely his, so why violate a written committment to freeze construction since doing so can't make it "any safer"? Answer: because politically he can not survive a prolonged construction freeze, and so he would have no choice but to negotiate in good faith and cut a deal, the sooner the better. And that is anathema to him.
Jerusalem light rail conductors striking over new train schedule (Haaretz)
from the article: Netanyahu rejects criticism of Jerusalem construction beyond green line