7.2 = 12 * 12 / 10 / 2
But having integers for ones' for lengths (e.g 90m rather than 84.4) does seem a bit nicer in a way.
I think you make a good point about 15 vs 7.5 and symmetries around 1/2/3/4/5.
It undercuts the 12-centricity though; 15-centricity is just so much more man-centered, not fitting for someone about to be beatified as a saint!
In a way, base-10-centric measurements are the victors of a three thousand year battle between group-by-10s beancounter arithmatical people in Egypt/Mesopotamia and the also ancient 12-centric make-things-easily-divisible architect/construction geometers.
True, 12 doesn't match the number of fingers or toes... but have you ever considered it does match the number of spaces around our fingers and toes?
We used to learn to count on our fingers instead of counting our fingers, our four fingers have twelve knuckles and our thumb is the pointer. There are quite a few schemes for counting and doing math on our fingers like this, some include the tips of our fingers as well or tips and two knuckles, or the segment between the joints or all of the above, and both hands for complex math and different fingers for different things like place so you could count higher and do math on larger numbers. Someone saying you counted on your fingers was once a compliment, only the unlearned would count in their head, too easy to lose place because of distractions.