How modern Israel came to be upon “God promised land”?
That’s the main reason and I do not believe in any possibility of any peace in the region, whatever bullshit politicians would say.
Tell me why anyone in the region shouldn’t be pissed of at Israel (and to their piggy banks in the West)?
That's not really an accurate characterization of the situation as much of the land was uninhabited/unregistered and/or state owned. The Negev desert for example is a large percentage of the total land area and was effectively uninhabited and not privately owned. Land ownership records at the time were also not particularly clear and often there were disputed claims. Also Israel has about 20% Arab/Palestinian citizens so it's not like they ethnically cleansed everyone like Egypt/Jordan did with the Jews in Gaza and the West Bank when Israel gained independence.