Why? 1m is about the length of one step (heel to heel)
> Fahrenheit is more useful than Celsius
Why? Freezing water has 0°C, boiling water 100°C.
> Pounds are more useful than kilos
By a numeric coincidence (gravity of earth is nearly 10 m/s^2) 1 kg has a weight of about 10 N. This makes it really easy when going climbing to compute what mass you can put on some part of the safety chain.
Generally: It is a pain in the ass to convert these non-metric units among one another. For one example 1 P̸ = 12p, 1 in = 6 P̸, 1 ft=12 in, 1 yd = 3ft, 1 mi = 1760 yd. Sounds very simple and logical to me. :-(
Alone this fact is for me argument enough for metric units.