Yeah. But when your own leader fails you, where can you go for help?

EDIT: My answer: They go to Hamas, because they can no longer trust the Palestinian Authority.

I am answering this based on the internal politics that leads to what happens now, and why the PA very slow in mitigating the crisis. The way how the world react, although relevant, is not the issue as per discussed by the news article.

There's more than enough blame to go around on the failure of negotiations, depending on who you believe. For example:

Clinton blamed Arafat after the failure of the talks, stating, "I regret that in 2000 Arafat missed the opportunity to bring that nation into being and pray for the day when the dreams of the Palestinian people for a state and a better life will be realized in a just and lasting peace." The failure to come to an agreement was widely attributed to Yasser Arafat, as he walked away from the table without making a concrete counter-offer and because Arafat did little to quell the series of Palestinian riots that began shortly after the summit. Arafat was also accused of scuttling the talks by Nabil Amr, a former minister in the Palestinian Authority. In My Life, Clinton wrote that Arafat once complimented Clinton by telling him, "You are a great man." Clinton responded, "I am not a great man. I am a failure, and you made me one."

Dennis Ross, the US Middle East envoy and a key negotiator at the summit, summarized his perspectives in his book The Missing Peace. During a lecture in Australia, Ross suggested that the reason for the failure was Arafat's unwillingness to sign a final deal with Israel that would close the door on any of the Palestinians' maximum demands, particularly the right of return. Ross claimed that what Arafat really wanted was "a one-state solution. Not independent, adjacent Israeli and Palestinian states, but a single Arab state encompassing all of Historic Palestine". Ross also quoted Saudi Prince Bandar as saying while negotiations were taking place: "If Arafat does not accept what is available now, it won't be a tragedy; it will be a crime."

In his book, The Oslo Syndrome, Harvard Medical School professor of psychiatry and historian Kenneth Levin summarized the failure of the 2000 Camp David Summit in this manner: "despite the dimensions of the Israeli offer and intense pressure from President Clinton, Arafat demurred. He apparently was indeed unwilling, no matter what the Israeli concessions, to sign an agreement that declared itself final and forswore any further Palestinian claims."[38] Levin argues that both the Israelis and the Americans were naive in expecting that Arafat would agree to give up the idea of a literal "right of return" for all Palestinians into Israel proper no matter how many 1948 refugees or how much monetary compensation Israel offered to allow.

https://en.wikipedia.org/wiki/2000_Camp_David_Summit

You need to ask Israel for that. That not the point of this article. The point is when Palestinian Authority fails, it creates a power vacuum - that's when the Hamas comes in.

You got downvoted but I have to upvote it as I perceive you got the underlying message . It works exactly as intended by Israel, although not favorable to the outcome of the real people they suppose to represent.