Most female shamans did not have too high of ambition because they preferred to get married and have children and thus lost a large fraction of their power in the process. Life in solitude was too lonely, and they could not live forever. They were still normal human beings that had to abide by the law of nature and must age and weaken along with their aging body. These shamans were very humble and did not have much ambition.
The same could not be said for male shamans, who although could not pass their power on to the next generations, were able to enjoy both having a family and being at the peak of their spiritual power.
This was especially the case for the shamans who had accumulated power from many previous generations, such as Xi'an.