Why?
The answer is simple. The Arab nations despise the Palestinians -- almost as much as they despise the Jews. They are using them as "useful idiots". If the Palestinians were to ever succeed in getting rid of Israel (fat chance), the Arab nations would in turn eradicate the Palestinians in a heartbeat.
Even so, there is a certain absurd humor to the spectacle of the wealthy Arab nations, crying like babies over Israel, which gives its Arab citizens the right to vote and sit in the Knesset, while they themselves -- the Arab nations -- won't even allow a Jew into their country.
The same bastards cry foul about the US, accusing us of being rude to them, by arresting some of the fifth columnists and terrorists they've put here. They accuse us of bigotry!
Imagine that. If an American Christian visits one of their countries, he cannot own a house, or land; he cannot practice his religion, even in his apartment; he cannot even enter some of those countries if his passport is stamped showing that he's been in Israel.
And, these same offended Arabs, who accuse Israel and the US of discrimination, because Israel will not allow unrestricted Arab immigration -- these paragons of Islamic virtue expelled the Jews from their countries a half-century ago, and will not let them return to their homes.
In summation, the Arab nations are like spoiled brat children. They demand everything, they concede nothing, they insist that the world kiss their ass, but they refused to allow anyone else the least bit of human dignity.
They demand full equality everywhere in every other country, yet, they are the most bigoted, discriminatory, hypocrital creatures on earth in their own countries.
And this is something we're supposed to respect?
Clearly, the diplomatic corps has become the last refuge of the worlds' surplus of unemployed comedians.
These fools would be laughable if not for one thing: they are dangerous. But laugh or not, one thing is certain: they simply cannot be permitted to come into the possession of nuclear weapons.
Sane nations, like the USA and the former USSR (who for all their bellicosity, were at least sane enough to not want to end the world), built nuclear weapons for one purpose -- deterrence.
In other words, the civilized nations of this world built these weapons so that they wouldn't have to use them.
Each sane, civilized nation hoped upon hope that it would never use its nuclear weapons.
However, this is not the case with this crazed throwback to the Dark Ages. It is chafing at the bit to get control over nuclear weapons -- but not for the reasons the civilized nations wanted them.
These madmen desperately want to get their hands on nuclear weapons for a different reason.
They want to get them, so that they can use them.
And if they get them, they will use them.
The world is poised on a precipice. I do not know if we have the foresight, or the courage to deal with things before it's too late. I hope we do, but I fear that we don't.
So, there's your answer to why the Arab nations don't offer the Palestinians some of their land. And I threw in a bonus answer for free. Ah, digression. I need sleep! :)