I agree that it’s a stupid idea (and on behalf of my nutritionally misguided country, I apologise…) for all the reasons stated.
And (of course) they highlight saturated fat, which is actually good for us, and ignore PUFAs, which are actually bad for us (at least in any quantity).
And they ignore protein and non-sugar carbs.
Apart from anything else, I think it would be difficult to implement (certainly implement with any accuracy) from a technical point of view.
(BTW, I certainly do look at my receipts, but not for nutritional information).