100% not agreeing with this person, but I think their point is that if Hamas attacks, their attacks are likely to be blocked by the iron dome, resulting in no Israeli casualties. But if Israel retaliates, Palestine will have casualties.
I think the thought process is to defend Israel by implying all the deaths they’ve caused is as a counterattack?
Again, not defending it, just interpreting what I think was being implied. Even if my interpretation is correct, so much is still missing from the thought process.