Theory: the US was a very early republic (it's probably almost the oldest contiguous one), and, at the time it was created, it was _normal_ for countries to have a degree of mysticism about their leadership (generally a monarchy).
So, it attached a certain amount of that magic to the 'founding fathers'. And this never entirely went away. Meanwhile, republics became more common, and, elsewhere, the need for mysticism faded (it's not even particularly common in actual monarchies these days, Thailand excepted). "Is this really what [whoever came up with the current constitution] would have wanted" would be a pretty weird question in most countries, those people being recognised not to be omniscient. But a fairly standard question in the US.
So, it attached a certain amount of that magic to the 'founding fathers'. And this never entirely went away. Meanwhile, republics became more common, and, elsewhere, the need for mysticism faded (it's not even particularly common in actual monarchies these days, Thailand excepted). "Is this really what [whoever came up with the current constitution] would have wanted" would be a pretty weird question in most countries, those people being recognised not to be omniscient. But a fairly standard question in the US.