I don’t think it’s pure curiosity. Maybe physicists are driven by passion, but everybody understands that new physics has historically unlocked a lot of new technology.

I also don’t think that the public really has much of a say in what gets tax payer funding. Governments are just bureaucratic behemoths and once they start paying for something, they can almost never find an acceptable way to stop. Additionally I’ve never met a tax funding recipient that was grateful to be getting it, if anything the perspective that they should be entitled to even more is a lot more common.