@Markerrag -- I think the metric system hasn't caught on in the United States for at least three reasons. First, we think of measurements in terms of imperial standards. We are inclined to think of distances in miles, inches, feet and yards rather than kilometers, centimeters, decameters and meters. Similarly, we think of gallons instead of liters when it comes to liquid measurements, and how hard would it be to translate recipes from imperial to metric?
Second, imagine the cost of converting to metric. Think of just a car and converting filling stations from gallons to liters. Think of drivers dealing with kilometers instead of miles (if the speed limit is 70 miles per hour, what does that mean in kilometers?)
Finally, who wants to be the first generation to make the transition from imperial to metric? Once the metric system is learned, it is easy but a lot of adjustments would have to me made and the brunt of that would fall on one generation or the other. It could be that people like the metric system, but want to shift the burden of transitioning to it to another generation.