I agree with both arguments: In my examples it doesn't look natural (and having such a boring box is really a worst-case but serves well to show the effect very clearly), but on the other side it must be seen in context (like others said before). While nature doesn't have "translucent" materials, this soft edge can be interpreted as a transition you can often see in the real world: be it, that a little bit of sand and dust from the ground sticks on the base of the object or just a variation of the ground-height which avoids an unnatural straight line between the two "elements".
It is of course a hack, and it doesn't work perfectly fine when looking so close at the box, but in my eyes it works very well for e.g. the stones. Unfortunately, I wasn't able to overwrite the shader to disable the blending in the game. I'd have loved to show how Deus Ex looks Without this effect.