This isn't true at all, lol. Aerospace in the US has used 'english' measurement from the start. My take on the matter is that all units are arbitrarily defined and flip flopping the units that we already use is a silly idea of progress.
The strength of the metric system is not on the particular dimension of their definition, but lies in the use of a decimal system. That is what makes it superior to the old imperial system and why the scientific community in the US uses it. Using a single base system for all your numbers, and the same base system as the one used in your numbering systems is the only way you can do complex computations without resorting to many magic numbers.