Why does my moto z play droid silence feature default to alarm only interruption?

[AC Question]

I just recently got a moto z play droid and have been trying to explore some of the functions to see what is similar to the moto x 2nd gen that I had. When I use the volume down button and click it past vibrate it goes to alarms only until you turn off do not disturb. When I look into the options for do not disturb it will also go silent if I manually tap that. In order to do that I have to drag down the top menu bar and click on the do not disturb. When I checked the settings and go into the priority only allows the option to turn off alarms is grayed out. Why can't I adjust that? If I want to silence my phone I don't want alarms coming through and should just be able to hit the volume button until it goes total silence.