"What was different this time was that it was Israel who was the victim."
You've just described the deadliest day for Jews since the Holocaust [1] as a blip because, in your accounting, it was Israel's turn to absorb one.
The "continuum" framing doesn't hold up numerically either. In non-war years, OCHA records roughly 100–200 Palestinian deaths annually at Israeli hands [2]. Hamas killed 1,139 people before lunchtime. That's not a blip in a continuum, it's five to ten years of equivalent deaths in eight hours.
The youngest victim was 14 hours old [3]. The oldest was a 92-year-old Holocaust survivor [3]. None of those facts change based on who you think had it coming.
[1] https://www.ushmm.org/information/press/press-releases/museu...
[2] https://www.ochaopt.org/content/casualties-thousands-killed-...
[3] https://www.yahoo.com/news/youngest-october-7-victim-just-00...
I would have figured the families of the Jews who built Israel would have realized "holocaust bad, never again".
What they learned was "never again to us".
Just because your family had a holocaust executed against them, doesnt give you any (legal, ethical, moral) right to run your own holocaust.
And Israel is running a holocaust in Palestine, and has been for decades.