In short, it's not.
Digging does burn a lot of stamina. Even more so when you get to the solid rock layer. Lots of time used, food and water used up. Time spent digging takes away from other things like scavenging.
Augurs do make lots of noise and attract zombies by the hoard.
Some blocks do fall on you, sand and gravel mainly but other dirt blocks do fall. I nearly got killed a few times doing so. So yes you do need support. So what's your point anyway?
But anyways. I don't see the devs saying (anything) about this. Nope, not a word. Well I guess it will still be just-as-easy to dig and hide in Alpha-17 IMVAO.
Isn't that right TFP's?