Their reason to destroy israel is because it oppresses them. Palestinians have very clearly shown to be open to negotiations. These get shut down by israel because israel wants to expand their Lebensraum.
So, about 20 years ago Israel left voluntarily the Gaza strip and give it to Palestinian, on the understanding that there will be peace, the Palestinian elect Hamas but somehow it is still Israel fault for being the oppressor.
This might come as a surprise but almost nobody is going to risk their lives fighting when they are not being oppressed.
The only problem is that Israel offered a peaceful way out, Hamas refused it. So now Palestinians have basically 2 choices: to be killed while being used as a human shields by their own people or help IDF to fight Hamas, with the risk of being killed but the possibility to build a better future for themself.