The Misty Mountains are so named because the fog that envelops them never disperses throughout the year. Hence, there's only a small part of each day when sunlight is visible in the mountains, while most of the time the sky is covered with a gray mist, limiting visibility.
Not to mention, most areas of the mountains are undeveloped primordial forests, and coupled with the continuous, intersecting mountains, this environment has limited the development of the Mountain Tribe while also becoming their Sanctuary.
It is pure fantasy for the external forces to think they can launch a main force attack on the mountains; here, the danger is not just the Barbarian Tribes, but more so the environment—everything will be consumed by the mountains.
Even Count Bastia, who oppressed the Barbarian Tribes, had to halt at the outskirts, giving up on going deeper.
Did he not want to?
He simply couldn't...
