There was never a "country" of Palestine, and the recreation of Israel in 1948 was probably the most legally up-and-up of that of any country (30+ years of international law behind it), in addition to being pretty much the greatest victory for decolonization of all time.
As for Wheels' question - here's the answer:
Lyndon Johnson said:
“If you can convince the lowest white man he’s better than the best colored man, he won’t notice you’re picking his pocket. Hell, give him somebody to look down on, and he’ll empty his pockets for you.”
The psychic wages of whiteness, Middle East edition, demanded that the Jews be a helpless and subservient victim population, remaining as such through 1,000+ years of constant persecution and massacres. Any advances to the Jews was an intolerable challenge to the social hierarchy. The recreation of Israel produced a violent reactionary backlash as have so many other advances in social rights for designated undergroups you can all think of. If Israel had the exact same military history but was run by Egyptians or Turks, you would never have heard of it.
Let's take a closer look at the history of Khamenei's country, Iran.
How did Israel, formed 1948, cause the antisemitic massacre in Mashhad, Iran, in 1839?
en.m.wikipedia.org
How did Israel, formed 1948, cause the antisemitic massacre in Shiraz, Iran, in 1910?
en.m.wikipedia.org
How did Israel, formed 1948, cause any of this in Isfahan, Iran, in the 1500s?
archive.diarna.org
After the ascension of Shah ‘Abbas II the Jews of Isfahan faced a lot of persecution. Most communities were forced to convert to Islam. Furthermore those who refused to convert would have most of their inheritance taken away as the inheritance laws at the time allowed for those who converted to Shia Islam to inherit the property of non-Muslim family members. Some communities did not convert and were thus forced to wear a special badge to show that they were Jewish. The maltreatment of the Jews weakened their community ties and influence throughout the region. By 1889 there were only around four hundred Jewish families left in Isfahan and most very poor.
How did Israel, formed 1948, cause these conditions all throughout Iran in the 1850s? From the Shiraz link above:
In the middle of the 19th century,
J. J. Benjamin wrote about the life of Persian Jews: "…they are obliged to live in a separate part of town…; for they are considered as unclean creatures… Under the pretext of their being unclean, they are treated with the greatest severity and should they enter a street, inhabited by Mussulmans, they are pelted by the boys and mobs with stones and dirt… For the same reason, they are prohibited to go out when it rains; for it is said the rain would wash dirt off them, which would sully the feet of the Mussulmans… If a Jew is recognized as such in the streets, he is subjected to the greatest insults. The passers-by spit in his face, and sometimes beat him… unmercifully… If a Jew enters a shop for anything, he is forbidden to inspect the goods… Should his hand incautiously touch the goods, he must take them at any price the seller chooses to ask for them... Sometimes the Iranians intrude into the dwellings of the Jews and take possession of whatever please them. Should the owner make the least opposition in defense of his property, he incurs the danger of atoning for it with his life... If... a Jew shows himself in the street during the three days of the Katel (the start of
Muharram)…, he is sure to be murdered."
Khamenei's entire identity and sense of social normalcy is based on the Jew being inferior, disgusting, and killable. Now that they got uppity, he is clinging to bitterness.