In 40 years of flying I have only seen a few nights, some but not many, where you could honestly say you could fly in an unstabilised helicopter with sole reference to external cues and not need to look in at the instruments.
Assuming you mean an AI, AH, T&B, etc., that seems extraordinarily unlikely, or at least extraordinarily your own experience, which perhaps is heavily slanted towards more challenging night VFR conditions. Not trying to put words in your mouth, just trying to understand. People have untold thousands (millions?) of hours at night in un-stabilized helicopters with no attitude information in the panel and seem to manage just fine at night under reasonable VFR conditions (not total blackness, but not brilliantly lit urban landscapes either).
If you are referring to airspeed, altitude, etc., heck, don't we all use those in all types of flight conditions?
For any newbies reading this particular thread of discussion, it's important to understand that different countries and different parts of the flying community do things differently. Part 91 operations in the US occur in ways that curl the hair of, say, retired UK military helicopter pilots. Needs must when the devil drives, and since US Part 91 op's are mostly in un-stabilized, un-sophisticated, light singles, as opposed to medium or heavy, fully stabilized, twins, you get the aforementioned un-stabilized singles flying around at night quite successfully, minus the occasional exception like the one being discussed herein.
In other words, it's not inherently evil, but one must understand the conditions they are facing and act accordingly and, most importantly, according to their own risk tolerance (damn, there's that risk thing again!) The risk tolerance of a lot of the Rotorheads on PPRuNe tends to be quite conservative. Nevertheless, remember that accidents (or "negligents") happen not because a helicopter or pilot is intrinsically more or less capable, they happen because someone exceed the capabilities of man and/or machine. Indeed, look at the other relatively recent topic about Rescue 111. If that had been an R44 they might have been dead quite quickly. It just took a bit longer for the far better equipped, trained and experienced crew of Rescue 111.
Anyone can push anything too far. That certainly seems to be the case here, and it's worth discussing the how and the why. But don't let it be an indictment of all VFR night helicopter operations.