The article says it pretty well. There are no horrible chirps, it'll alert you in a humane way that hey, your battery is low and you need to change it. They've

The article says it pretty well. There are no horrible chirps, it'll alert you in a humane way that hey, your battery is low and you need to change it. They've clearly found a problem (current alarms suck) and have made a solution. Just because you don't see the convenience doesn't mean other people don't, as is clear from the comments here. Once you get burned by regular smoke detectors in the middle of the night, you would pay good money for a product that actually fixes some of these issues.