I agree. I have an American made car that is 1/2 metric and 1/2 US standard. What a pain to be under that thing and not knowing what size your looking at or need.
It all started in late 77 by the big 3, Ford being the odd ball with sizes like 11 and 17 mm , costing me more in tools every day and dont get me started on metric thread IMO uss and sae bt far better threads and easier to work with IMO