Did you guys know that alarms still ring when your device is set to silent? So during the night you can increase volume and silence ringtone, then when you wake up you can decrease volume and unsilence! Isn't that amazing?
I don't think you've really captured the many combinations of ringer and alarm volumes that might be desired in this 'solution'. There's the possibility of forgetting to do one or the other, for a start; why should you have to manually intervene every morning and every evening on a smartphone? I have turned off using the hardware buttons for ringer control to prevent accidental adjustments of it, and so changing the alarm volume requires going into Settings >Sounds.
As amazing as you think that is, it would be fair more amazing, and simpler, to have a dedicated volume slider in the alarm app.
What's really confusing me is that people thought alarm and ringer had separate controls before iOS 7, as if iOS 7 took away this feature. Really? Am I just dumb or really forgetful? I don't think this ever existed, for example see this:
https://forums.macrumors.com/threads/1254529/