I get the feeling that half of f.ds things I'm a moron; 99% of the other half things I'm an idiot.
You've left out the possibility of trolling.
21.4mU/l
11.2pmol/l
Can someone equate this to numbers I understand? Remember, this is SI, not Imperial. I have no frame of reference for this -- so what if it's base 10? Even if I know how many milliliters are in a liter, that doesn't help me at all.
There is no SI unit with the symbol U, so I've no idea where you're getting that (do you mean u, the atomic mass unit? I guess that makes sense in context, though it's not an SI unit). Interestingly, the liter is also not an SI unit, though it's approved for use with SI--I guess you could call it extended SI? Let's look at the other.
Units of pmol/L. Let's write that out as picomoles per liter. This is a unit of concentration that's 10
-12 moles of a substance per liter. The mole is an odd SI unit because it's not based directly on powers of ten; it's defined naturally based on the number of formula units of a substance in one gram of the substance, which turns out to be 6.022 × 10
23 for any substance.
I've never seen anyone use units of atomic mass unit (amu for short, symbol u) per liter. It... doesn't make any sense. The number you give would be a literally homeopathic concentration, i.e., less than one atom per liter.
If someone is better at dividing by 12 than by 10, that's not the system of measurement's fault.
You've described exactly zero humans. Every society now uses mathematical systems based on the number ten. While English and other (Indo-European) languages still have words that fit with a dozenal system, and those words are sometimes used for
counted objects, no one can divide by 12 faster than by 10, because the former requires math, and the latter requires only moving the decimal point.
If you want to postulate an alien society that has 12 symbols for numbers and uses dozenal math--and therefore, for whom moving their sub-fractional indicator one space to the left would be dividing by 12--then, OK, I suppose aliens are unlikely to use SI.
So, when you remove the users from the equation, and try to appreciate each system in a vacuum, it becomes a subjective discussion about what any one person finds pleasing, right?
Only if some of the users are aliens.
I think the Imperial System is much, much more regal, for example. Metric feels very pedestrian and bland. If measurement systems were ice cream, Imperial is chocolate and Metric is cardboard. Imperial presents the more interesting set of vocabulary, with words that fit oddly in the mouth like "quart" and "pint" (which, by the way, is how we measure ice cream). Only in the imperial can you see for leagues and leagues or lose yourself in the countless fathoms of the deep ocean. In Imperial you can have a gill of water, a rood of forestland, or drachm of poison.
This isn't the most ridiculous argument I've heard for the US customary system, but only because appeals to tradition and "some people might divide by twelve more readily" are both worse. Seriously, you're going to suggest that a system of units is better because the names sound more interesting? While there certainly have been scientists who have become poets and writers, they still kept the poetry out of their scientific papers.
This example also points up a major flaw in your reasoning; the ancient units aren't all based on division by twelve. Consider length, because it's one I know, and one that uses 12 in
exactly one conversion.
4 inches = 1 hand
3 hands =
12 inches = 1 foot
3 feet = 1 yard
22 yards = 1 chain
4 rods = 1 chain (making 1 rod... 16.5 feet, try to divide by 16.5)
10 chains = 1 furlong
8 furlongs = 1 mile
3 miles = 1 league
There are 6 different numbers you need to remember here, not counting the other conversions that you need to remember because no one uses chains or furlongs (1760 yards = 1 mile, 5280 feet = 1 mile). And that's just for length! Now contrast to the commonly-used metric length units:
1 micrometer = 1000 (10
3) nanometers
1 millimeter = 1000 (10
3) micrometers
1 centimeter = 10 millimeters
1 meter = 100 (10
2) centimeters = 1000 (10
3) millimeters
1 kilometer = 1000 (10
3) meters
--------
Now let me blow your mind about something. The word "mile" comes from the Latin root "mille," same as the prefix "milli-". This is because originally, 1 mile was... 1000 paces. Even the Romans had already figured out that powers of ten were useful.