What I'm doing here is not "criticizing" the US' "position and stance on the metric system". What I'm doing is trying to determine the truth in the assertions given.
The US is really behind in terms of metrication when compared to the whole world. Metrication there goes at a sluggish--almost indolent--creeping pace. This is a fact. This is true, and is admitted by many in the US. Of course that's an embarrassment. Having two competing systems of units in a globalized world is ridiculous. Especially when one of them is outdated, based on principles and concepts obsoleted long ago.
Here's something for you to think about.
For pretty much every other country on the planet, metrication made a lot more sense and benefit to the average Joe. For instance, if you're a rather small country there are great benefits to trade by standardizing on the system your nearby trading partners were using. In Europe, in particular, there seemed to be such a hodge-podge of units that picking a single system was a great benefit. It didn't really matter which one you chose, and since metric had various benefits over the more traditional systems, it sort of won.
In the US the situation was different. Way back in 1793 the US realized that there was a need for a standardized system among the states since they were too using their own horrible mixture of units, largely imported from the various countries that the residents came from. In fact, the secretary of state at that time, Thomas Jefferson, was in fact interested in this newfangled metric system and requested information from France. France thought it was a great idea and sent a scientist and a copy of a kilogram to the US. Unfortunately, said scientist and kilogram were intercepted mid-route by a raiding party of British Privateers who ransomed the scientist and auctioned off the kilogram.
At some point shortly thereafter, not having a proper kilogram reference, we standardized on our own version of the British system of inches and feet and miles and pounds and so on.
It should be clear at this point that for the next couple hundred years or so, all of the major trading partners with the USA were on the same system, so for the average person, there wasn't much reason to switch. Even if you were exporting/importing the need for metric was minimal. We built all of our own stuff and exported largely non-mechanical items. If you look at things which were manufactured even 50 years ago you'd find that most of them were made in the US. So, the reason why we went to the moon on customary measures is that's what our industry was tooled up for, and what everyone was familiar with. Doing that work in metric would have been much riskier.
Instead of thinking "why hasn't the US moved to metric", you need to think about this more like the following: Until 50 or so years ago, largely the systems dominated and trading with Europe were using the metric system, and North America's and Britain's trading partners were all using the customary system. There were, of course, some exceptions. And the majority of the trade was done in each zone in those units.
So now we need to move to the '60s-'70s. At this point, the government has decided that it would be better to be on Metric. So they start spending money on converting. Britain, under pressure from the EU also caved about the same time. Canada got tied up in the whole thing too since they were close to the US and also was a British commonwealth. A lot of people seem to think that Britain and Canada are fully metric, and although they are far more outwardly metric, they certainly are not 100% metric. In fact, if you look at the history of Metrication in both Canada and Britain you'll find very similar situations to what we have here, with metrication not really being fully completed in any of these countries. Yes, they're both farther along, but not nearly as metric as some would think.
A lot of the active resentment in the US encountered during this big push is exactly the same resentment that would have been felt if the US tried to impose it's measurement system on the rest of the world. There was a system in place which worked for hundreds of years and now the government wants to cram this new system which has no real benefit for the average joe down his throat. People didn't like it, and the US at that point didn't really have any financial incentive to do so since the number of things being imported/exported for which metric mattered was minimal. The US taxpayers also really don't like to see taxpayer dollars being thrown down the tube. The idea that large amounts of money were being spent to change all our road signs to a unit that no one in the US really wanted or cared about caused a lot of taxpayers to give their elected politicians an earful. This pretty much resulted in that part of the experiment being shut down.
Imagine for a minute that metric was the inferior system - how would you feel about being forced to change from something which has been working perfectly well for years?
So, we're pretty much stuck where we are. The roads are not getting metric signs anytime soon. We'll buy gas in gallons, and a lot of things will pretty much always be customary because the average person sees no reason to change. Houses will still be built using feet and inches because that's what the building materials are. And forcing a change those would not be politically wise since those are visible changes, and people don't like change.. What is really happening though, and as we've been trying to explain, is that pretty much everything else is being converted to metric slowly but surely. I'm not going to rehash the last however many pages of what is and isn't converted, but I see more and more things which are metric every day.