Why don't Orcrist / Goblin-cleaver and Glamdring / Foe-hammer glow like Sting when orcs/goblins are near?
In the book, they did.
Chapter 4, Over Hill and Under Hill, page 64:
Suddenly a sword flashed in its own light.
(Gandalf wielding Glamdring the Foe-Hammer/Biter)
He took out his sword again, and again it flashed in the dark by itself. It burned with a rage that made it gleam if goblins were about; now it was bright as blue flame for delight in the killing of the great lord of the cave.
Why they don't in the movie, is never said. I can think of no in-universe answer.