You can even set the phone to automatically silence everything every night, but still let through phone calls from certain contacts in case of emergency.

Then you would be muting also alarms. You can configure complex setup and what not, with some sounds buzzing and some not, but people want one button solution and simplicity (for good reasons).

Just checked and the alarm still ringed despite phone being muted; at least on my phone, alarms need to be muted explicitly.