[AnIdiotOnTheNet]

It's a reflection of the mindset we hold about wealth, part of how we justify why one person deserves more than another.

For instance, why does some billionaire have significantly better health care than I do? Because they're worth more. Literally, they are more valuable to society than I am.

If you phrase it the other way: "because they have more money than I do", the justification isn't there and you'll have to question your societal model.

[Maybestring]

It's a quirk of English that we copied over our general words for amounts from our language for morality.

We might have chosen mass as an anlogy, and Jeff would weigh $100 billion. A very heavy man.

[wollw]

We could also honestly say he's talented and be pretty sure he weighs at least 75 pounds[1]. It occurs to me that part of the problem is the analogous thinking in the first place, but even I (someone who was planning to take a vow of poverty at one point) have to admit that monetary worth is supposed to indicate how valuable/good of a person we are in normal circumstances; it's the reason to reward. Where it loses meaning to me is where there, like sjk alluded to, isn't even money but the assumption of it. There is nothing to actually show for it as stock options, money in the bank (unless it's really a vault), even Federal Reserve Bank Notes if you want to invoke the significance of them historically as essentially checks that could be cashed for silver and gold: it's all imaginary and kind of delusional to think it is really Wealth. As a result one of the more interesting things happening in the Financial sector to me right now is the Royal Mint's introduction of Royal Mint Gold as it challenges the entire idea of Fiat Money by using blockchain tech like a deed for gold ownership. It makes me think of Gringotts.

[1] https://en.wikipedia.org/wiki/Talent_(measurement)

edit: I'm inclined to add that I view gold and silver as actually valuable in part because they're physically useful in production of at the very least Artwork, which is what a coin is. There is an interesting division in the United States between the Mint and the Bureau of Engraving and Printing that draws a line between the purification of metal and the printing of bills that carries a lot of significance: purified metals represent purity whereas printed paper money is always being thrown out and burnt as it falls apart and has little material worth. One is timeless Art in that it is an actual indication of purity and the other is a mashed up pulp of cotton and flax with ink strewn over it that absorbs our human filth (oils and such) until it falls apart.