Why did they start firing rockets 75 years ago? Did they just fire it to Israel for no reason?
No, they had a very good reason: They hate Jews and do not believe Jews have any right to national sovereignty in their own land.
No - they just don't happen agree with them on the question of whose land it is.
You don't have to agree with their historical reading of the situation, of course. But it's really quite straightforward and simple, really. And if people are firing rockets at you -- it's probably best not to invent outlandish and unreal explanations for why they're doing so.
In any case -- pretending that the rest of the world obviously and unquestionably accepts the idea that this is all "Jewish land" (now or in 1947) -- or that if they don't, it's because the simply hate Jews, or won't accept the idea of Israel existing in any form -- definitely isn't helpful.
(And no, I'm not justifying or "explaining" the firing of rockets at anyone - please don't go there).
For whatever reason most people don't get that. I came to live in Germany around 15 years ago during the economic crisis and was pretty shocked that it was normal to say in public that Greeks are lazy. I couldn't understand the difference between that and "Jews are evil" and similar rhetoric that led to the Holocaust. And that in the country that should've learned something from the past. This time around I am not surprised they are fully behind this genocide simply because it's more convenient to look the other way.
Shame.