Yeah most military and police aren't being suddenly woke up from a sound sleeping and suddenly grabbing a weapon in a dark room.
They have time to prep and get their sling on probably, and aren't fumbling around with a sling in the dark half asleep.
And if you just grab the gun in a hurry without mounting the sling it's gonna be a snare hanging there waitting to snag.
What the "pros" do doesn't always apply directly to the situations you might encounter at home in your bed at night.
You sure aren't giving people any credit. When it comes to making assumptions about the training, experience, and knowledge of others I give the benefit of the doubt. I would appreciate it if you returned the favor.
But I will address your points, as they apply to me personally, in hopes that you will come to realize why making a bunch of assumptions and then applying them, in a blanket manner, to everybody, is not likely to work very well
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My room has plenty of light for the task. There are night lights all over the house, including one directly behind my rifle, and 2-3 others providing light to the bedroom. I have multiple battery powered night lights that come on even brighter if power is interrupted. Seeing my way around, even in the dead of night, is not a problem...
especially with dark adapted eyes. And who says every HD situation will be woken up in the dead of night anyway?
Getting the sling on is very simple, and very easy, and can be done very quickly. Grab sling with off hand, lift over head, push hand through sling. Done. I have done it many times and don't even have to think about it.
If I don't have the 0.5 seconds necessary to get into the sling, I won't be picking the rifle up at all, I'll be sticking with the handgun I got off my nightstand before I even got out of bed. Or, if I don't have the time, it's because somebody made it into the bedroom very very quickly, in which case I'll be shooting from where the rifle is, and there won't be anything to snag the sling on anyway (nor the movement necessary for that to happen).
I have outdoor lighting, passive defensive landscaping, securely locked/reinforced doors and windows, two large dogs, and a monitored alarm. Chances are I'll never have to use an HD gun. If I do, chances are I'll have the few seconds necessary to get to it and pick it up. Also, the adrenaline dump will make sure I am no longer half asleep.
If I need to use my hands for something, it is probably going to be better to have the rifle hanging in front of me, by the sling, than having to set the rifle down on something (or just let it fall). Dropping it into the sling is faster than setting it down, easier than setting it down, and keeps it where I can go right back to it, if necessary.
I have moved/ran around and maneuvered with the rifle slung, and it rarely gets in the way enough to be a concern.
I have moved/ran around and maneuvered with the rifle in my hands and the sling 'on', and it has never come close to snagging on anything. Further, given where the sling is, getting caught on something seems quite unlikely.
There is no reason that everything in my post cannot apply to anybody/everybody else.