It's actually slightly worse than we may realize.
First is there is no requirement in the certification rules for an attitude indicator in a Part 27 helicopter for even night flying. (Read Part 27 if you don't believe me), and check what the baseline, absolute bare bones equipment is that comes with most light helicopters - attitude indicator is an optional extra.
How can we allow this?
Second is the definition of VFR- it probably has been hammered at before, but it states something about navigation and orientation of the aircraft by use of visual references. At night, regardless of the visibility, if you're over the water or unpopulated territory, you can't really orient the aircraft by use of visual reference.
What do the insurance companies think about this? Might be good to have them consider an attitude indicator minimum equipment, and night flying as IFR, unless you are going to be staying over downtown.