Answer
The cost of conversion from English system to metric system is more than the benefits to be realized.
Work Step by Step
Where the whole world has started using the metric system of measurement because of the ease and its uniformity, United States is still not able to accept the metric system and is still using the English system of measurement. The main reason behind this is the machinery industries.
They stood against the metric system because every tool, designs, and machinery in the country was based on the English system. All the infrastructure of the United States were based on the English system units. It was argued that the cost of shifting from the English system to metric system would be much higher than the expected benefits from this shift.
This is the reason the United States is not able to change to the metric system, even though they accept that it is a more beneficial and uniform measurement tool.