Mooncup --
But Israel must realise that this sort of brutality drives more Palestinians to Hamas. Israel seems to have a need to escalate situations far beyond what is necessary or justifiable.
Yes Israel is sowing dragons' teeth. But Israel has concluded that it is impossible to win friends in the ME and would just as soon be hung for a sheep as a lamb.
The campaign currently under way is a means of demonstrating that any escalation of attacks on Israel or Israelis, any acquisition of better weaponry (Israel encountered at least one drone iirc) by Hamas or anyone else whose declared aim is to wipe out the state of Israel, will be met with a determined use of utmost force necessary in the situation.
It is also meant as a demonstration to ISIS as to what lies in store if its attention is turned from Iraq and Syria. There is no reason to believe ISIS will not try to have a serious go at Israel. The entire ME, including the Gulf States, Jordan, Lebanon are all worried about ISIS. The initial hesitation of the US to respond to the ISIS threat in Iraq has left the ME worried that they may all end up on their own facing ISIS.
If Israel had kept roughly to the 1947 borders or at least not occupied the West Bank and Gaza Strip from 1967 then she would probably have been at peace for decades. Every time the Israelis escalate like this they make their future more dangerous, not less.
This particular escalation is taking place in a window of opportunity given by the recent suppression of the Muslim Brotherhood in Egypt and the (de facto) takeover of Egypt by the Army. The campaign Israel is pursuing is against the MB and its clones in the West Bank. All of this is happening with the tacit backing of Egypt, which is equally keen to see the end of the Brotherhood.
OP -- the Netanyahu exhortation to Palestinians to 'leave' is a reminder to Palestinians that they are pariahs in the ME, that nobody wants them as refugees, nobody will give them military support or help them build decent housing, hospitals, schools, etc, and it is thus also a way to signal that Israel has the backing of Egypt. It is a caustic way to put all of that.
And yes, although Israel has the support of the US it is a plank of both Democrat and Republican foreign policies the statement that Israel can only rely on itself is a reference to America sitting on its hands during the Holocaust. It is also a reminder to the US (in a caustic way again) that America left it too late to help the Jews of Europe, and it is also a reference to recent American failure to act swiftly against ISIS in Iraq.
It also shows that the Israeli-American relationship is somewhat akin to a ride on the back of a tiger. This is appreciated by some members of Congress and some sections of public opinion, but nothing will be done about it as long as the US is also assured of oil from the ME and Libya. (This harkens back to Netanyahu's 'leave' statement's meaning that Palestinians have no Muslim friends and that the very, very rich states of the ME are happy to ignore their misery).