US Declaration Cards given out even though they were unnecessary

Last year, I flew on Emirates from Milan to New York (JFK). Everyone was given US declaration cards, and I filled it out as required. However, when I arrived at passport control, there was an automatic machine that processed me, which also made me answer some basic customs questions, thus rendering my paper declaration card unnecessary. (However, I do want to note that they didn't ask for things such as an address in the US, unlike the paper card). At that point, I thought that maybe Emirates wasn't informed of the ATC yet and so was still giving out paper forms.

However, this year, I flew the exact same airline on the exact same route, and again I didn't need to show my US declaration card.

In other words, my question is: Why does Emirates keep handing out paper declaration forms if they aren't used at JFK anymore? Does it have to do with the fact that the questions on the paper are more detailed as on the machine, so they are kept as some sort of proof in case you need it? Or do maybe visa-holders need the paper form but ESTA travelers, Americans, and the like don't? But then shouldn't the airline know which travelers to hand them to and to which not to?

Note: I am a US citizen so maybe that has something to do with that. Also, relating to a comment, even if the FAs had simply been offering the declaration cards (which I'm quite sure they weren't, everyone had gotten one and I don't remember being asked if I wanted one), it shouldn't be up to the passenger to know if they need one or not; that would require them knowing for each and every single airport if the ATC would let them be processed or not. It would be much simpler if the FAs asked if you had an ESTA, what nationality you have, etc, wouldn't it?