Yes, it is always acknowledged that violence has been on both sides pre-1948. The debate is about post-1948, Israeli oppression of the Palestinians, which has led to apartheid and racism.
Israel was not a justified creation. The Balfour declaration was made by UK - a colonial power, who took land that did not belong to them, and gave it to a people who did not live there for the most part, without consulting the actual people living there. It was a classic case of colonial paper partition.
Boris Johnson, the former PM of the UK said this about the Balfour declaration:
“bizarre”, “tragically incoherent” and “an exquisite piece of Foreign Office fudgerama” . He further went on to say -
“Another way of putting it might be that the British government viewed with favor the eating of a piece of cake by the Jewish people, provided that nothing should be done to prejudice the rights of non-Jewish communities to eat the same piece of cake at the same time”.
However, today, it is a legitimate state. The same way Canada and the US are. Canada and the US were also colonial endeavours. However enough time has passed, and people have developed an identity, that these are legitimate states. Same as Israel.
Also watch this: