People keep taking the rating borderline seriously (and will do) because that "arbitrary" choice was somehow only partially arbitrary. It had a solid vision behind it, and it has it for the rest people. 6.0 for entertainment is a Moon run, it's just how people are taking it (including me), simply because they have the idea of how a clear Vault and a clear Moon runs look like, how entertaining they are.
So we can still judge in a similar fashion. And it appears, this run does indeed belong to Vault, because most of the raters didn't give it 6 or more for entertainment. I do believe they also consider 6+ a Moon rating, and intentionally don't give it.
turska: this is a weird case. Vocal feedback would have been the same (clear Moons), and the ratings will still disparage it. One can never be sure, because:
[2214] Coleco Jumpman Junior by adelikat in 04:48.58