Problem with units

After spending nearly three-quarters of a year in US, I am still finding it difficult to place quantities expressed in pounds, inches, miles, ounces, pints, quarts, fahrenheit, etc. Every time I encounter them in a grocery store or a liquor shop, I have to do the arithmetic. It is simple but I hate the fact that I have to do the conversion to get a sense of the magnitude.
I have never quite understood the reluctance of the Anglo-Saxons to accept metric system. Especially so in the States, where there is a lot of emphasis given to practical convenience in everyday life. That being the case, it is quite strange that people prefer units are related by unwieldy constants as compared to the simple ratios in powers of 10, that characterizes the metric system. When you can revamp the language and make modifications to both the spelling and pronunciation of words on the grounds that it is more natural, why the hell would you not change this inconvenient and confusing units to something simple and direct? It is true that people have become used to it but should you not make the switch when it is a better option.
Most parts of the world have adopted the metric standard . And what's more, even in Britain, there is a law that requires all products to carry the metric units as well. Now, that makes the continued insistence on using "English Units" another example of American Exceptionalism.