You people can downvote me all you want and the fact remains that the costs to make the switch are too high to happen any time soon. The real world isn't your company where you can just mandate things. Stakeholders, such as voters, get a say. Voters probably wouldn't support this if there was a net benefit in cost, but there's not, not anymore.
Of all of the things that are broken about the US, everyone here wants to fix the one thing that's not: our ambidexterity with units. Every school child learns both. We're terrible at raising kids to be bilingual, but we manage to teach them both metric and imperial units.
Once you concede that the metric system is already in de jure use in the US and in de facto use in domains where it's best to use it, you lose all kinds of benefit from switches. The low hanging fruit has been picked. You're left with empty non-empirical arguments like ... ummm... it's better to use one system. It is! But we're not starting from scratch.
Seriously, of all of the things I have posted on HN none has gotten more downvotes than saying that we don't need to go 100% metric in the US, I could speculate as to why, but it sure seems like this is some kind of nerd anti-normie shibboleth. It shouldn't be.
Go ahead, look up the figures. Then decide if it's still worth it to you. If it is, then try and convince enough policymakers not to just support it as the US does but to change everything over. You won't win that war. There has to be some specific need for the change.
'It would be cool' or 'it soothes my OCD' or whatever aren't enough to change something this massive.
Most problems it's a dodge to say "the money is better spent on X" but when you're talking about significant fractions of GDP that's just not how it is. We could do so much to improve people's lives with these sums of money.
Reminder that this is all about the US government internally sticking with letter sized paper. A4 paper is still A4 when measured in inches (which can be done exactly since inches are defined in terms of meters).