I'm sure you realise that when taken like that, any measurement invented is arbitrary of course. We have to invent a set length before we can benchmark it systematically. The imperial system cleverly uses a range of reasonably logical measurements such as 'feet', but it's a system that is more prone to becoming inaccurate and confusing as time goes on. It simply doesn't make as much sense as the metric system beyond the very basics by which the measurements are defined. (eg, how do you define a meter to a person who has never seen the length of a meter, as opposed to defining one foot, which is roughly one foot.)
Where metric makes more sense than imperial is the simple use of predictible scales when increasing or decreasing numbers used in measurements.
1kg = 1000 grams
1l = 1000 ml
1l weighs as much as 1kg
100 cm is a meter
1000 meter is a kilometer
I am 181 centimeters tall, 1.81 meters, or even 0.0018 km - as opposed to I am 5 feet and 11.26 inches (or is it 5.94 feet?) or 71.26 inches.
No person unfamiliar with the imperial system would be able to tell you what a mile is in inches, or even feet if they're particularly slow on calculations.
Having said that, whatever you're used to is undoubtedly what makes the most sense to you, as the issue surrounding this discussion is perspective. You grow up with imperial and it makes sense, much like your native language. Strange 'languages' have a different set of logical rules that may or may not make sense to you. It's probably a lot harder to get used to the imperial system if you grew up with the metric system than vice versa though, although that's pure speculation. The metric system just seems to have a more structured 'grammar' (gotta stick to the language theme here :P)