In THE HOBBIT, I always thought it was a bit odd that when the goblins of the Misty Mountains attack Thorin's party, they don't actually attack the dwarves themselves, they steal their ponies-- and the dwarves risk their lives trying to get them back, and get captured. It seemed a little extreme to me, especially since (in the book at least) the dwarves are mostly unarmed.
But then I started backpacking and realized that if you lose your gear, you could be in a bad way. On my hikes I am, at most, maybe six hours walk from a forest road, and another two from a highway and a reasonable expectation of help. So the bear (or the goblins, should leave their lairs in the Winding Stair Mountain) can have my tent and sleeping bag, and food and everything else.
I am NOT, I should emphasize, out on the slopes of the misty mountains. In that case, I might have to just roll for initiative against that bear and take my chances. Thorin's dwarves don't have much in the way of weaponry, but they do have a lot of gear, and they have ponies to carry it-- and the goblins go after both the ponies and the gear. So it's a much more desperate situation than it appears at first glance. Sure, they can survive the rest of the night in the cave, but what Happens to Thorin and Co. the next day, or the next?
Of course, that's exactly what happens later (and these are SPOILERS, for the one or two of you who haven't read THE HOBBIT) in Mirkwood. They don't have much equipment (goblins took it), and what they do have (thanks to Beorn), doesn't seem to be enough, especially the food. Which leads to wandering off the path to try to hunt, and then trying to beg from the elves. The elves leave 'em lost in the woods to be devoured by giant spiders.
So, lack of equipment leads to getting eaten by giant spiders. Or, put another way, small disasters lead to panic, which lead to big disasters.