John Michell summarized the case against the metre (and, by extension, other metric and "SI" measurements) as: it doesn't measure anything.
This is why metres - their decimal divisions and multiplications - are almost useless to think with; whereas many of the Imperial measures are very well suited to inner work: each being a measure of some thing relevant - whether inches, feet, furlongs... or leagues.
[The league ought to be revived, as being the distance an average person walks in an hour. Of course, you need some artificial device for measuring hours - which have no natural correspondence!]
For examples: Understanding the height of everyday objects in feet and inches, or weight in stones and pounds... These are far superior to the metric substitutes.
(Although I don't understand why Americans have abandoned stones - so that peoples' weights are stated given in very large numbers of pounds! This goes absolutely against the common-sense spirit of Imperial measures.)
My favourite instance is the acre as (roughly) defined as how much land could be ploughed in a day - thus an acre in areas with light sandy soil might be several times larger in area than an acre in heavy clay soil; and this difference broadly reflected the agricultural value of the land.
It strikes me that metric measures have only replaced Imperial to the extent that people have stopped being aware of their environment, and ceased thinking about things for themselves.
And have instead handed-over their thinking to machines and computers - devices that just tell us stuff in arbitrary, abstract and incomprehensible terms...
And we are intended uncomprehendingly to submit and obey (and, nowadays, people nearly always do...).
The one bad non-SI measure - which has, significantly, spontaneously (by popular lack-of-demand) been abandoned almost everywhere - is Fahrenheit, which (significantly) is not Old English in origin.
The Fahrenheit doesn't measure anything (in ordinary experience) whereas its more successful rival, the metric (but not SI) measure of Centigrade is rooted in the freezing and boiling of water.
Yet a Centigrade is - as typical of such abstract decimalizations - the wrong size for everyday usage: been too big, too coarse, a measure; so that in practice half degrees Celsius (or less) must be used.
The practical men who devised Imperial measures would have subdivided the difference between freezing and boiling into a larger number of degrees (maybe twenty-four?); and probably in accordance with what was most useful for the usual everyday purposes of measuring temperature - which occur in the lower half of the range.
Note added: By my understanding, however, all mathematics, arithmetic, geometry, number-systems &c are abstractions that remove us from direct (i.e. relational) participation with reality. Just that the Imperial measures are less abstract, more rooted in human experience... It is a matter of degree, not a qualitative distinction. But there will be no Measures in Heaven!
