Want to know how well public air-raid bunkers work against advanced bombing technology? Check: https://en.wikipedia.org/wiki/Amiriyah_shelter_bombing and that's 30 year old tech.
This question is one of the talking points of the Pro-Israel side. It's not that bizarre. But yeah, as talking points go, it's shallow/simplistic. The idea is to demonstrate that Hamas couldn't care less about Palestinian lives. They don't invest in any shape or form in protecting the citizenry or making the lives of Palestinians better. It's also meant to contrast with how Israel invests in protecting its population- lots of shelters for a much larger population, Israel has been building shelters in various forms forever. During most of the cold war Israel has been facing enemies with fairly unlimited resources as well, rockets, ballistic missiles, large air forces, even artillery (the north of Israel used to be regularly shelled by Syria way back). So it is actually possible to use shelters as a layer of defense.
Israel's more recent strategy of reinforced spaces in every house/apartment (started IIRC when Saddam Hussein decide to lob Scud missiles at Israel) has worked fairly well so that could be replicated in Gaza. Israeli buildings have taken direct hits by rockets from Lebanon and Gaza with pretty decent survival rates even when the building itself was practically demolished. Though that might require using the concrete for something else than tunnels. Oh no, another talking point.
The better strategy though is not to get into a situation where you're being attacked with bunker busters or try to separate civilian infrastructure from military infrastructure. Other ideas is that when you're warned about an area becoming a subject to aerial bombardments you move away. Sorry, more talking points.
Jordan 3,240,000
Syria 630,000
Lebanon 402,582
Saudi Arabia 280,245
Egypt 270,245
Qatar 100,000
Kuwait 80,000
Iraq 57,000
Yemen 55,000* I say "these folks" because I don't know that I agree.
Fixed it for you.