Yeah, John Oliver got that one completely wrong. Israel's policies should be debated, but the full context can't be forgotten. Hamas acts as a surrogate for Iran, just as Israel is a surrogate for the US. The Palestinians have had 70 years to agree to a peaceful settlement, but chose both to reject all the offers, and to re-elect Hamas. Hamas routinely resorts to Jihad practices that violate conventions; Indeed, few of their actions are NOT war crimes. Israel's responses may seem disproportionate, but that is how war is fought. If it were as terrible as the critics claim, the Palestinians would choose peace.
Again, the fundamental issue is this: The liberal and progressive wings also get Iranian propaganda and money for supporting the Palestinians, and for ignoring the record of Palestinian intransigence. People like John Oliver can get a laugh and be current, but he really should be better appraised of the situation, or he chooses to go with the herd. The situation is complex and can't be reduced to a one-liner. Oliver's take is shocking because he usually does his homework. One can only wonder why this became an exception.