I am using a liquid detergent and I use exactly the half of the detergent they say I should use. If a the washing machine requires 1 cup, I do half. Mostly because I don’t trust the company to put me over their interests.
Now, what will happen? Will my clothes end up staying dirty? Will it not remove stains which a full cup would have removed? Will surfexcel kidnap me and torture me for not obeying their commands? Help meeee!!
If (hypothetically) they specifically guide you to use more than necessary, thus wasting detergent, theyre making you spend more money on their product, thus extracting money from you.
Microwave popcorn isn’t a reasonable analogue because you don’t “use more product” following their instructions. Maybe hot chocolate is a good example? Every package I’ve bought has suggested using basically 2x as much as I find I need to make a mug of it.
Unless trial and error come into play, which is why I brought up popcorn. I honestly wonder how many of those complaining about this actually do laundry. Too much detergent ends up making the clothes seem like they went through a car wash, so if too much was being used, it’s not like the person wouldn’t know. There also aren’t as many hard rules about it as people think there are to base the idea of some of the purportedly “wrong” specifications on.