Personally I don't object to oil companies selling whatever products they want to, so long as they are clearly and honestly labeled as to what applications they are suitable for. By clearly I mean in large print on the front label.
I DO object to a company selling a product labeled "Motor Oil" in large print on the front label when it is not suitable for 99% of the "motors" on the road, and then placing it on shelves alongside bona fide modern automotive motor oils. This fools innocent consumers who don't understand motor oils, who are probably over 90% of the population.
I believe most of the oil companies doing this, as well as many of the retailers, know exactly what they are doing. They count on consumers not reading back labels, or understanding the API and ILSAC symbols and acronyms. It appears they also target low income neighborhoods where people are more likely to be attracted to lower prices. That's pretty low!
If you want to sell an SA oil for compressors, fine, label it "Compressor Oil" on the front label. If you want to sell another obsolete oil, fine, label it "Vintage Motor Oil" and state on the front label "Do not use in engines built after 19XX." That's simple basic honesty, so why do you think they don't do this? Could it be that the would sell a lot less oil? To bury such limitations on the back label is just plain intentional trickery. Fraud laws are justified to prevent corporate abuse, protect average consumers, and create a level competitive playing field. How well such laws are written is another topic.
NOTE: I am an unpaid advisor to PQIA and the opinions I express in my posts on BITOG are my own and do not necessarily reflect the position of PQIA.