Don't be fooled by adorable babies zooming down curiously empty roads.
According to Miller, the reason for this is that most newer printers have "integrated plumbing" that could get clogged by "expired ink." If consumers want to avoid this, ahem, "feature," Miller suggests that they buy printers with an "integrated ink cartridge," as they don't have the kill switches. A little easier said than done, considering that HP doesn't list which printers do and don't have "integrated ink cartridges."
So why not just put the easily cloggable plumbing inside the cartridge? That way, instead of having to waste our money on temperamental cartridges, we could just toss the ones that get clogged. The printer companies decided they'd rather sacrifice our money so that they can "put more ink in the cartridge." More ink that you likely won't be able to use. This actually works out OK for an office, where they do tons of printing and will run out of ink long before it "expires." But the tens of millions of home users who aren't printing out lengthy manifestos every day are forced to toss countless perfectly good ink cartridges if we don't use them fast enough.