If someone is able to take care a piece of land more than someone else, doesn't the person hold some value in its restoration?
Not necessarily, no. I can't look at a derelict apartment and claim that because I can take care of it better than its current owner, I should be entitled to its ownership.
Besides, it was Israelites that were there first, then it was Palestinians, and now Israelites just want the land they originally had back. Makes sense to me.
Well, if we take irredentism to its logical conclusion, we then have to ask whether the US, for example, should be submitted to Native American rule because Native Americans were there before settlers arrived. The same goes for Australia, Egypt (since Arabs also arrived after conquering it), and multiple other countries. History is, of course, an important part of the discussion, but irredentism alone oversimplifies the issue.
The technology that the Natives had was stagnant. The tribes that were here before us were at war and had no unified sovereignty. If Americans had not settled in the West, our world would have shaped much differently, and probably, much worse than it is now. There was opportunity to claim land that was being under-utilized by the Natives and thus we shaped it under one sovereign democratic republic. To suggest anything less is anti-American and anti-Western values.
I don't see this as relevant here or have any interest in pursuing it, as I find it both tangential and apologetic toward genocide. However, I would suggest considering that many Americans and others from Western countries, quite possibly the majority, would certainly reject the assertion that denouncing the genocidal and supremacist notion of Manifest Destiny is anti-American or anti-Western.