This may be another hold-over from our fixed wing brothers.
They have limits on the glidepath angle they certify, because for them, glidepath and approach and minimums can be a problem.
Basically, if you want more than 4 degrees of glidepath, as a limitation for your instrument approaches (Category 1 minima), then you have to demonstrate the approach at 2 degrees steeper than the glidepath you want.
Ditto for tailwinds - more than 10 knots (the limit on most airplanes, even if not explicity stated it seems), you need to demonstrate an approach with 50% more tailwind than you get cleared for. Want 15 knots of tailwind - demonstrate it at 22.5 knots.
And for both cases in multi-engine airplanes, demonstrate an engine failure at decision height and either land safely or go around.
Why all this fixed wing talk?
Because we often get saddled by the same criteria.
In this case, the glidepath angle should not be a limiting factor, as all the ILS glidepaths are within this limit. (Perhaps Stephenville Nfld is steeper than this, but hey, who goes to Stephenville?)
The problem is going to come when we eventually throw off our chains and get real helicopter approaches, like Nick talked of earlier, and which I was lucky enough to fly - awesome, and why aren't they being put into use?