All 3D applications have grid, and Photoscan should not be an exception. Grid helps to understand where you are in the world, and know how the model is positioned and oriented in space. Axis in the right bottom corner is not enough. The fact that it’s not present in Photoscan now, just blows my mind.
For you to understand what we do now, is to decimate the model, export to external software like 3dsmax and look on it, check if it’s oriented and positioned ok. This isn't comfortable. I think it makes perfect sense to do it.