If Palestinians they gave up their designs on killing as many Israelis as possible and driving them from the Middle East, they could greatly improve their quality of life. Every concession from Israel has resulted in outrage from Palestinians and more Israeli deaths. If they were to give Palestinians the "right of return" and give them full control of all the lands they want, Israel would cease to exist within months.
As far as the BDS is concerned they have no such defence. They know that it is already causing harm, they know the Palestinian authority/Hamas are oppressing their own people and have a policy that requires the destruction of Israel, they know that if they succeed then Israel will be destroyed and many of its people Arab, Jew and Christian will be at best kicked out at worst killed en masse. Ignorance isn't an excuse either because at this point they have to be willfully ignorant.