I know he was serious. The concept is great if you think about it. Test various archetypes and their subsequent perks without spending valuable resources. That's cool by me.
No. The concept is dumb. 80% or more of the perks in this game do not even trigger unless there is an enemy around. Tell me how, in a firing range, you test out Hidden Hand, Zen Moment, Outlaw, Firefly, Exhumed, Danger Close.... Shall i continue?
You want Bungie to build a firing range so you can test Hand Laid Stock vs Rifled Barrel? Just think about that for a second...
The targets could be considered enemies. That fixes the perks that requires enemies near you. Then, if you shoot a target, it displays a damage number when you hit it. That fixes all the range, damage, and perks like that.
No but if you could always go out and hunt deer, wouldn't you? Plus, have you ever once shot a deer that was moving? The practice, in that situation, fits the task you are practicing for. Plus, it's always Dreg season in Destiny. No need to kill time in a practice range for you to be legally aloud to kill a Dreg.