Speaking to any Alexa device mutes whole house - why not zones?

So, it's great that when I'm in the living room with music playing and I speak to the Echo in the same room that the volume automatically mutes on the Sonos gear in the same room. However, I find it kind of silly that it mutes Sonos equipment in other rooms.

For example, it's 8am, I'm downstairs in my home office, listening to the news or some music on my Play:5. My wife's getting ready to head out to work, and in the bedroom, which is on a different floor and at the opposite end of the house. Both doors are closed too. She takes a moment to ask the Echo Dot in our bedroom about today's weather. And my Play:5 gets muted, despite being nowhere near where she is.

Why not group into zones to prevent this? Like "Upstairs Echo & Living Room" get grouped, and "Office Dot & Office" get grouped for muting purposes.

I can't see any options in either the Sonos app, Alexa app, or the Sonos Alexa Skill to do something like this, so if the capability exists, it's pretty well hidden.