Personal preferences are one thing (I have great difficulty thinking of my petrol consumption in the car in anything but miles per gallon).
In aviation, I can see excellent reasons for using knots and nautical miles. I see little reason why we should not convert to altitude in metres and windspeed in metres/sec.
I dislike fuel gauges in lbs. You tend to run into problems with ordering fuel in pounds, getting it on the bowser driver's sheet in litres, accounting for it on the trim sheet in kilos, and then being back in pounds for consumption purposes. Remind me - where IS Gimli?
Kilos (or tonnes) and litres for fuel makes total sense. Weight (kgs) = Volume (litres) x S.G.