[Bud]

Remember that it's not 14 prefixes, or at least not 14 new ones. We're just talking about a couple new ones. There's only a new prefix for every three orders of magnitude, and everyone is already very familiar with the small ones. And there are mnemonics.

And we're not asking the layman to know all these, either. Zepto- will never be in common use; that's for particle physicists and basically nobody else, so far at least.

Everyone already knows 10^12=tera, so we're covered there.

[LeifCarrotson]

-21, -18, -15, -12, -9, -6, -3, 3, 6, 9, 12, 15, 18, 21 is 14 prefixes.

I think the number of people who could (correctly!) name even half of those is much smaller than you think.

[danbruc]

You are missing - 24, -2, -1, 1, 2, and 24 for a total of 20.

[cyphar]

±1 doesn't require a prefix, and while in Europe "deci" is used in common parlance for units of power ±2 it's not really used in scientific or engineering terminology globally. I'm also not sure what real quantity you're referring to which requires the power ±24 prefix (yes, the term "yottabyte" exists but no measurement of data capacity uses it).

[danbruc]

±2 are centi and hecto with centimetre and hectopascal probably being the widest used ones, ±1 are deci and deca with decibel probably being the widest used one. For deca I can also not think of any real usage.

[Avamander]

Yeah, but the number of people who actually need to use those units do know how to name them.