Your claims of impracticality would make a lot more sense if you could point out people using the metric system who say it's impractical. Meanwhile, can you tell me how many yards are in a mile? How many pounds are in a ton? How many pints are in a gallon? The relationships between these measurements are nonsensical and impractical.
1760, 2000, and 8
For what it's worth, I'm a scientist and love the metric system as much as the next guy. And yet, there's still something to be said in using units that give "nice" numbers for things that you do all the time.
So in scientific experiments off the top of my head I often use:
mT instead of T for magnetic field
mbar instead of Pa for pressure
mW instead of W for laser power
mA instead of A for current
GHz instead of Hz for frequency
and so forth
Granted those are all metric based (although bonus points get awarded to those who knew 1 mbar = 100 Pa without looking it up), but I also often use:
eV instead of J for energy
amu instead of kg for mass
atm instead of bar or Pa for pressure
"beta" (v/c) instead of v for velocity
light years instead of m for distance
and so forth
which aren't really related to metric units at all. And heck, I've even got a scientific vacuum gauge that measures pressure in "inches of mercury". Go figure!
So I completely understand those who want to keep using English units for everyday life because they are often more convenient than their metric counterparts. (And frankly I feel that same way about deg. F myself, most days. Not a huge deg. C fan.)