You're attributing to me a statement that I haven't made, but only reported from one of your comments in response to one by formulaT. I've never said that Palestinians are the
only legitimate people in Palestine
now (note the
now, I'll get back to it later). What I'm saying is that the fact that in a remote or recent history a Jewish, or Palestinian, or Martian political entity or group or people has existed on the territory is completely irrelevant to the issue at hand, as long as those people had been away for long enough for other people to consider that place their own home, and that of their fathers and grandfathers.
Now, you seem to think that it's fine for any group of people in any number to move in mass to some land, as long as they buy their lot of ground and don't steal from others. But as you must certainly understand, it doesn't work like that. There's plenty of empty space in the US, do you think that US citizens would be ok if a few tens of millions of Chinese, or Mexicans, just moved to some empty part of the country and started to build a new nation? Of course not. Every nation in the world, including Israel, has strict immigration laws to prevent immigration in uncontrolled numbers - building a new sovereign state is completely out of the question. And the reason every nation has such a law is that a people rightly considers the land it lives on its own, even the unoccupied parts, and even the privately owned parts to some extent. You can't declare the independence of your house from the nation, even if you paid for the ground it stands on.
Ok, so the mass immigration of Jews in a country in which their number was absolute minority (Jews were 13% of the population in Palestine in 1890) was wrong, and illegitimate. They took advantage of the fact there was no organized nation in place, and all the support they could get from a colonialist state, Great Britain, to move in mass to a land that was occupied by other people. The reason it's wrong is clear when you look at what came from it: mass displacement of the native population, pogroms, war and terrorism from both sides. Clearly it's something that doesn't bring anything good.
But let's get back to that now. Israel was born officially in 1948, and its population was already of one million. That means that most Israelis are born there, and probably their parents were born there as well. Most of them literally don't have anywhere else to go. What are we meant to do to repair the wrong of the illegitimate constitution of Israel, move war to it and force its population to abandon their belongings and disperse again? That would be doing to them exactly what they've done to the Palestinians, and that would be as horrible. So Israel is there to stay.
So, to recapitulate:
1) The remote history is irrelevant, it doesn't change the fact that to take possession of a land you have to displace the native population with violent means - and that's exactly what the Jews did.
2) Moving peacefully to an empty land and do what you please with it is an idea that might seem reasonable to an eight years old; that's not how it goes and facts show it.
3) Therefore, mass immigration in Palestine with the purpose of building a Jewish state was illegitimate and wrong.
4) Now that the Israelis are there you can't force them out of what has become their home. What you must do is to force them to establish a clear border line with their neighbours and to recognize them as an independent and sovereign State (yes, with an army and planes and bombs); to dismantle their illegal settlements and force the settlers to live inside those borders. Dismantle the wall, that they will rebuild as they please inside their own borders, not outside as they did before.