It's a strange ruling to require even facing earth because of this verse I think it would annul any requirement to follow a direction if it's difficult or impractical.

2:177 Piety is not to turn your faces towards the east and the west, but pious is one who believes in God and the Last Day, and the angels, and the Book, and the prophets, and who gives money out of love to the relatives, and the orphans, and the needy, and the wayfarer, and those who ask, and to free the slaves; and who upholds the prayer, and who seeks purification; and those who keep their pledges when they make a pledge, and those who are patient in the face of adversity and hardship and when in despair. These are the ones who have been truthful, and these are the righteous.