Yes, if I said “hand me the scissors” it would just be one tool with two blades. I could also say “hand me a pair of scissors” to mean the same thing. Kind of like how “pair of pants” or “pair of glasses” mean just one of those items. For reference, I am from the US. Not sure if you meant English as the country or as the language. Either way, those usages are nonsense and I will happily keep using them.
If that’s true why aren’t the sugar water pools in rainbow order. Folks, let’s not get tricked by fake news. The real threat is rainbows and, of course, double rainbows.