Yeah - that way they don’t have to call it Partial. 
I think the nutrition per 100 grams label works well with people who are comfortable doing some quick math in their heads. It’s easy for me to very quickly grasp how many 100g portions are in the package and it’s easy for me to see the “kcals per 100g” label e.g. and quickly estimate how many calories are in the portion I’m eating. And I’m American and not used to metric things.
The only serving size that matters is the size of the serving you serve yourself.
That’s exactly the kind of bullshit marketing you avoid with 100 gram labeling.
For all of the shitty stuff in China, this is one of the things that I sorely miss. I can look at any label and understand all of the nutritional information I need per 100g. Back here, everything is up to the manufacturer. On the other hand, I don’t have to memorize what “carbohydrate” and “fiber” look like in Chinese.
I’ve bought items imported from Finland, Sweden and other countries that haven’t.
Old-fashioned ice cream scoops, it is.
Yes, you can figure out how many 100 gram amounts are in the package easily enough, but you don’t know if 100 grams is a serving, or half a serving, or 2 servings, or whatever, until you take the package home, open it, take out the amount that is a serving for your meal, and weigh it. Not useful for deciding, in a store, if you want to buy something or not, or if it’s worth the money.
Some people have to keep stricter track of their intake than others, and knowing the amount considered a serving, in terms of diet, not marketing, is important.
Yes, of course, it is easy to see how many 100 g amounts are is a package. But, again, is 100 grams a standard serving or the item in question? The packaging of the item doesn’t tell you if the optimum amount of the food in the package it 22 g, 50 g, 75 g, 100, 150, 200, or whatever. You can guess, based on density of said item or familiarity with it, but generally not helpful for purchasing.
Optimum amount of food depends entirely on the person and their situation. “Standard serving” sizes is completely arbitrary. Nutrition per 100ml/gr is not. And it’s fairly easy figuring out how much you get out of 100ml/gr by comparing with the total contents of what you purchase, which is usually provided.
But that problem exists independently of whether the label gives the amount by 100g or doesn’t even give a single line. And some of us actually know what’s a serving size of common foods by weight: my serving size for “dry” pasta or rice is 60g and 40g for soup, independently of the type of pasta or rice. A teenager’s about 150g (100g). If you don’t happen to know the same for you, that’s a personal problem no amount of labeling will solve.
Sure. But how often is 100g what you would really eat?
It’s even easier to figure out how many “servings” you are about to consume, and multiply the “per serving” nutritional info by that number. Nobody expects that number to be 1 for everyone, but it’s safe to assume that it’s a fairly small integer for most people. Whereas 100 grams / 100 ml may be 1/5 of a serving for some things (e.g. bottle of soda), and 400 servings for something else (e.g. cooking spray).
There’s no such thing as a “standard” serving though. This whole thread has been evidence that serving sizes are chosen by the manufacturer deliberately to manipulate the nutrition label.
Case in point, Tic Tacs. Tic Tacs are 95% sugar. But because FDA labeling laws allow you to claim “zero sugar” if there’s under half a gram of sugar per serving, Tic Tacs are exactly 0.49 grams apiece. One “serving” per Tic Tac. And that’s how Ferrero gets to market a candy that is 95% sugar as “zero sugar” and “low calorie”.
Games like this are played with every item on the supermarket shelves. Your “standard serving” is just one of the game pieces. It’s no standard at all.
Sure, but I will never use 100g of cooking spray, so wouldnt it be more useful to see how much a pan worth is?
And 100ML is far too small for many beverages.
100ml/gr is just a round unit, applied to all products. It’s not necessarily tied to serving size, and it’s not really the point of it either. It is there to tell you how much of what is in 100ml/gr of a product, usually coupled with how much of what is in the total of the product, regardless of much you should consume.
And it’s not easier to figure out using serving size, since that can be whatever regardless of nutritional content.
NETA:
And why would you need serving sizes for cooking spray? 
Because when I use cooking spray, I want to know how many calories (or how much fat, or whatever) I’m getting from it.
What the average person really wants to know is “How much fat / calories / sodium / Vitamin C / whatever” am I going to ingest when I consume the amount of this product that I normally consume? “Amount per 100 g” isn’t going to answer that question for me, without me doing some additional calculations. “Amount per serving” will, if the amount in a “serving” matches the amount I actually consume, or is something easy to work with, like “1 package” or “1 bar” or “3 cookies.”
How would you know the amount you spray is a serving? Do you spray in a measuring cup before applying it?
And again, 100gr is a fairly small amount that is easy to calculate with by account of it being a round number, so I presume that’s why it is used as a standard. And that is really the argument for it, it is a standard. Anyway, I think I’ll bow out. If you can’t see the value of universal standards of measurement I probably can’t convince you.
I can see the value of both the “per 100 g” and the “per serving” methods. I think that which one is more useful or convenient depends on the context.
Any hand sized bag of chips divided into multiple servings is a joke. NOBODY doesn’t finish a small bag of chips.
Likewise multiple servings on soup cans. Come on.