What makes you think Costco has decreased the amount of salt used on its Kirkland mixed nuts?
The "salt Nazis", as you call them, really don't care about the salt sprinkled on snacks such as nuts, or potato chips, which is generally very minimal, they are concerned with the considerably higher amounts which are often hidden in processed and prepared foods.
What's your idea of "almost no salt" in a container of mixed nuts? How much sodium do you think should be reflected on the nutritional label of mixed nuts in order for you to be able to taste it?
Because the salt used on mixed nuts is all on the outside of the product it is easily tasted, so manufacturers can use very small amounts and still achieve a product that does taste salty. With salted mixed nuts, they generally need just enough salt to enhance the flavor of the nuts without interfering with it--people who want to eat mixed nuts obviously want to taste the various nuts, and not just have a salty taste in their mouth, because different nuts have distinct flavors.
The amount of salt used in mixed nuts seems rather standard. Both Costco's Kirkland Mixed Nuts and Planters Deluxe Mixed Nuts contain about the same amount of sodium, 75-80 mg or 3% per serving. Planters also makes lower salt and unsalted varieties, to cater to other consumer preferences.
As you say, you hadn't eaten these mixed nuts in a while, so maybe your taste memory was faulty, maybe they were never as salty in taste as you remember, or maybe the quality of the nuts used by Costco has changed.
Or, as ehBeth has suggested, your taste perception might have changed with age, or with the amount of salt you generally tend to use.
So, the mixed nuts you had might have been as "reliably seasoned" as they ever were, but your taste preferences, or taste perception, might have altered over time. You may be accusing the nut manufacturers of doing something they are not actually doing. Those, like Planters, who do offer varieties with lower salt content, do it quite openly.
let the taste buds decide, damn it!
They do decide. People like you are free to add more salt than is the standard, and people who like a less salty taste might opt for the Planters lower salt or unsalted varieties.
And, if you go to the Costco Web site, and read the customer reviews for those Kirkland Mixed Nuts, you will find some people complaining that they taste too
salty and requesting that they be made in a lower salt variety or with less salt. So some people have quite different perceptions of this product than you do.