Why did Zeus choose Hephaestus to marry Aphrodite?

Hephaestus was born very small and sickly, because of this, Zeus and Hera threw him off Mount Olympus, causing his leg to be broken. He was nursed back to health by the sea goddess, Thetis, but his leg remained damaged so badly, he was lame. When he grew up and became such a renowned blacksmith, the gods offered him a forge on Olympus, and to make up for casting him out as a baby, Aphrodite's hand in marriage.