Everyone can live as a mortal, all they have to do is never cultivate... but no one with spiritual roots does it, even cultivators with pseudo spiritual roots take the route of cultivation. In the end, it is because of the allure of long lifespans and unimaginable strength.
This allure is too enticing to give up for anyone. Even if you cultivate till some lower realms, your lifespan and strength will increase far more than mortals, so who wouldn't want to cultivate?
The only problem is once you start the path of cultivation, your greed increases... you always want to achieve more, as the lifespan and strength increase is tremendously higher for higher levels. So much that cultivators don't mind taking risks which can kill them—it is quite contradictory.
Maybe some cultivators cultivated in the beginning just to achieve a particular realm and live their life happily afterwards, but watching someone stronger than them, who can kill them in seconds, breaks their spirits.
