Oh, she's not miserable. My horse has a herd of about 10 horses who are in the same situation. Tons of hay, lots of shelter and water, and they are all very fat. If she shivers now and then, it won't kill her. She'll have her coat in very soon and she actually a bit overweight to begin with.
I would care very much if she had no way to keep herself warm. If I hauled her, she would get a blanket for the trip. If I clipped her, she would get a blanket to stay warm. If she was a horse who didn't grow a thick coat, she would get a blanket. If she was ill or underweight, she would get a blanket.
She has everything she needs to survive. This is the LEAST of the crazy weather we have seen. If she can't make it in this weather, I'd be very, very concerned. This is nothing compared to -40 degree weather my friend's horse go unblanketted in. It was 35 degrees out. Hardly scarey weather at all.
I'm sorry that I don't pamper her like a pet. Shoot, I don't even pamper my pets that way. And I'm sorry that its considered cruel now not to do so. But this is the way I keep her, and she has thrived on it for several winters. I don't see a reason to change it.
I guess my mare has more common sense than some horses, because she has never been pampered and knows where to stand to get out of the rain, wind or snow. She uses the lean-to when she doesn't want to get wet, regardless of if the whole herd is in there or not. No, she's not in the wild. But she's also never had someone bolt out and chase her down to toss a blanket on her because it reached 35 degrees.
I do believe that they start depending on us to keep them warm and dry if we let them depend on us for it. They forget how to do this themselves because its done for them. Much like rehabbed wildlife. At the facility I volunteered for, we had to keep human contact with the animal at a minimum and had to keep feeding as naturally as we could for them, so they wouldn't start depending on humans and seeing them as a food source when set free.
Taking the horse out of the wild doesn't kill its natural survival instinct. Taking away the need for survival does, however. My mare (along with any horse I've ever owned) knows how to take care of herself like her species has done for thousands of years without human help since she is given the supplies to do so. None of my horses were ever pampered in cold weather, and they all knew what to do. I like knowing that she doesn't need a human to keep her dry and warm. She can do it herself with the shelter that's provided.
I think we humanize the horse too much. Its cold out, so the horse must be cold. What do humans do when its cold? We wear a coat, so we think our horses need one. No, not really. If you give the horse the things it naturally needs to keep itself warm, it will keep itself warm. It doesn't automatically become stupid because its behind a fence. It becomes stupid when humans do the work for them (ie: blanketting in 35 degree weather) for years and years and so when the human finally stops, they have no idea how to handle themselves.
This, of course, does not go for the horses I mentioned aboved (underweight, ill, under developed winter coat, clipped or hauled horses etc.)
And those who were seen dancing were thought to be insane by those who could not hear the music