why is this direction given importance?
It  is also the direction for entering the "ihram"
Qibla
The qibla is also the direction for entering the "ihram"
the hajj was a turning point in muslim history The qibla  is the direction towards the Kaaba in the Sacred Mosque in Mecca, which is used by Muslims in various religious contexts, particularly the direction of prayer for the salah and hajj pilgrimage
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Qibla [SEP] Introduction
The qibla is also the direction for entering the "ihram" (sacred state for the hajj pilgrimage); the direction to which animals are turned during "dhabihah" (Islamic slaughter); the recommended direction to make "dua" (supplications); the direction to avoid when relieving oneself or spitting; and the direction to which the deceased are aligned when buried. The qibla may be observed facing the Kaaba accurately ("ayn al-ka'bah") or facing in the general direction ("jihat al-ka'bah"). Most Islamic scholars consider that "jihat al-ka'bah" is acceptable if the more precise "ayn al-ka'bah" cannot be ascertained. The most common technical definition used by Muslim astronomers for a location is the direction of the great circle—in the Earth's sphere—passing through the location and the Kaaba.