These two men, if reports are accurate, are from Pakistan. If so, they and their families have never been subject to violence from Jews or “Zionists.” (Although from my time living there, I can attest that casual anti-Semitism and insane anti-Israel conspiracy theories run rampant despite Israel’s profound lack of interest in Pakistan and the local Jewish community numbering in the triple digits).
In Pakistan, the Muslim majority regularly inflicts great legalized violence on religious minorities including Muslims who have an unsatisfactory theology. It is quite literally written into the legal code.
At some point, they traveled over 7000 miles to a multi-ethnic, secular democracy, presumably because their home nation— which by constitution is established and exists for Muslims with others merely tolerated at best— offered fewer material opportunities. Some years later they carried out a family mass shooting of Jews celebrating a holiday at a beach.
They are not the victims of generational violence committed by Jews or Zionists, and they are not mentally ill. The have willingly consumed a potent and vicious ideology that holds that all Muslims are victims of Israel and that Muslims have been unjustly dispossessed of their rightful heritage of political power over non-believers.
This is not an interpretation of Islam that all, or even most Muslims adhere to. But it is also not completely insignificant and fringe, sometimes more so in emigre communities living in places where religious tolerance and freedom is a given. Many of its adherents and proselytizers find more freedom of action outside of Islamic majority nations because most of them use state power to ensure that political Islam colors within lines acceptable to authorities.