In ArcMap, you can zoom to whatever scale you like, you always know what scale you're at, and you can choose from a drop-down of commonly used scales--or define your list of common scales for the drop-down box. AGX has a drop-down of "named" scales that I don't find very useful--something like World, Country, etc.
If it's a stretch to display the numeric map scale OOTB or provide a freeform zoom to scale box, then at least provide an option to turn it on. GIS for Everyone should not be synonymous with GIS for Dummies. I haven't used Google Earth, but does Google hide the map scale and disallow zooming to the scale of one's choice? One might say that people use AGX mostly to consume web services (and these have fixed scales). But AGX also allows one to add local data (shapefiles, gdbs, etc). It's frustrating to be able to do that, yet not have any control over which scale one is at.
There is an experimental Add-in for some of this (great start), but it needs to be core OOTB functionality: