Because setting alarms on normal clocks is really annoying. Or setting the time in the first place.
I assume the clock has wifi to set the time via ntp already, so adding an app was easy, in the eyes of the hardware division, who never think about the complexity of software, or the cost of it.
It's a job you do once though. Or very, very rarely.
It's surely not annoying enough to buy an alarm clock you can only set via and app on your phone which also requires you sign up for an online account. That, to me, sounds far more annoying. I'll stick with my £5 digital alarm clock.
I have an alarm clock that sets itself based on some radio broadcast of the current time. You need to set which time zone you're in and there's a single switch to turn DST on or off.
These don't do too well in the Eastern US. WWVB is too far away. They introduced a phase modulation that has a lower SNR required for recovery, but as far as I can tell no chipsets exist that understand this signal, and only one clock exists that can receive it. (And it's an analog wall clock, so good luck with your alarms.)
I use GPS for time transfer. Works great everywhere in the world.
> Because setting alarms on normal clocks is really annoying.
I'm not sure, on the two digital clocks I'm using, changing the time or the alarm takes at most 30 s. On the other it will ring every day at the same time, including on week-ends, but then since it's quick enough to change the alarm it's not a big deal. If I wanted day-of-week dependent alarms, I'd use my smartphone for this.
I assume the clock has wifi to set the time via ntp already, so adding an app was easy, in the eyes of the hardware division, who never think about the complexity of software, or the cost of it.