I certainly agree with you when it comes to salt and sugar. As for things which are very light and/or used in very small quantities, I think that using spoon measures is fine, especially for spices/herbs, where the worst that can happen is that your sausages or your cure is a bit over-spiced or under spiced. In the case of curing products, I think it's fine to use spoons as long as they are pre-calibrated and used consistently and meticulously.
Although one CAN perfectly well buy electronic scales accurate to 0.1g I find that with a tiny amount of mental effort, I can recalculate a cure mix to use exactly one british standard teaspoon (of the type I have) of - for example - saltpetre and therefore end up with a cure that is in exact proportions.
I'd no more use cups for measuring salt than I would for measuring beef or butter.
All the best - Ian
"The Earth is degenerating today. Bribery and corruption abound. Children no longer obey their parents, every man wants to write a book, and it is evident that the end of the world is fast approaching." c. 2800 BC