Why rebuild Gaza?

A cynical joke in Israel defines ceasefire as the Israelis cease, the Arabs continue to fire. 
Except it isn't a joke.

A month and a half after Israel ended its campaign to stop rockets launched by Arabs in Gaza destroying Israel's southern territory and killing and injuring Israeli citizens

In an official protest to the United Nations, the Israel's Ambassador Gabriela Shalev noted that "there have been nearly 100 rocket and mortar attacks from the Gaza Strip" since the ceasefire on January 18, or over two per day. These have been increasing in number, with 12 rockets were fired at Sderot on March 1 alone.
More landed in Israel yesterday and today. 
So Daniel Pipes asks
Was I the only one rubbing my eyes in disbelief yesterday, as the Egyptian government hosted an "International Conference in Support of the Palestinian Economy for the Reconstruction of Gaza"? (snip)
I wonder if those eminentoes and worthies really believe that warfare in Gaza is a thing of the past, and that the time for reconstruction is nigh?
Apparently those who live in fantasy land--and that includes the U.S. Secretary of State Hilary Rodham Clinton (D)--believe peace is defined by continuing to fire rockets, spewing hate and promising more, and worse, is yet to come.  In other words, reward war by Arabs and punish Israel for wanting peace.  (Tellingly, no one nation offered Israel even a penny to reconstruct the large areas of Israel damaged by over seven years of daily rocket attacks.)   At the conference
 in Sharm El-Sheikh, attended by delegations from 71 states, plus 16 regional, international, and financial organizations. Its stated goal was to raise US$2.8 billion, of which $1.3 was for rebuilding what had been destroyed in the course of Israel's recent war on Hamas (the rest would be sent to the Palestinian Authority to help improve its standing). The actual amount raised at the conference was $4.5 billion which, when added to previously committed funds, means the grant total for Gaza and the PA comes to $5.2 billion, to be disbursed over a two-year period. A delighted Egyptian foreign minister called the amount "beyond our expectations." U.S. Secretary of State Hillary Clinton called it "a very productive conference"
 Clinton has now seemingly succumbed to the Obamamessiah aura, thinking the two of them can succeed after more than 3000 years (long term) or 61 years (short term) of failure to convince Arabs to accept the existence of Jews/Israel.

As Pipes speculates

My best guess: this permits them subtly to signal Jerusalem that it better not attack Gaza again, because doing so will confront it with a lot of very angry donor governments – including, of course, the Obama administration.
Adding to the surreal quality is a blithe disregard for Israel's security needs. Consider the attitude of Douglas Alexander, international development secretary for Britain's Labour government, who pledged £30 million of his taxpayers' funds to rebuild houses, schools, and hospitals in Gaza. "There is a desperate need for tough restrictions on the supply of goods to be relaxed," he said, demanding next that "Israel must do the right thing and allow much-needed goods to get through to those men, women and children who continue to suffer."

That's very humanitarian of Mr. Alexander, but he willfully ignored Israeli expectations that Hamas will confiscate steel, concrete, and other imported construction materials to build more tunnels, bunkers, and rockets. After all, Hamas appropriated prior deliveries intended for civilians, and so blatantly that even the usually docile United Nations Relief and Works Agency protested.

Why then are they doing this? Pipes suggests
Is this ignorance or mendacity? I suspect the latter; no one is that dumb.
I respectfully would like to extend that answer and slightly disagree.  Yes, they are that dumb; they believe their "mendacity" will go unnoticed, be believed by those who want to justify the destruction of Israel. 
And then they can all proudly say they've finally solved the problem.  After all, that's the way its historically been handled.