The Song Dynasty avoided Yuanheng due to his ineffective leadership and the political instability he brought about. Yuanheng's reign was marked by corruption, weak governance, and a lack of effective military strategy, which led to the loss of territories and weakened the empire's power.

The Song Dynasty, known for its cultural and economic prosperity, faced significant challenges during Yuanheng's reign. Yuanheng's reign was characterized by his indulgence in luxury and his preference for the company of eunuchs over capable advisors. This led to a decline in the quality of governance and a rise in corruption. According to historical records, during Yuanheng's reign, the government was rife with corruption, with officials often neglecting their duties and engaging in bribery and embezzlement. This was compounded by Yuanheng's lack of interest in military affairs, which left the Song Dynasty vulnerable to external threats.

One of the most significant consequences of Yuanheng's reign was the loss of territories to the Jin Dynasty. The Song Dynasty's military was weakened by Yuanheng's neglect, and the empire was unable to effectively defend its borders. In 1127, the Jin Dynasty captured the Song capital, Kaifeng, and forced the Song court to flee to southern China, marking the beginning of the Southern Song Dynasty. This event, known as the Northern Song Dynasty's fall, was a direct result of Yuanheng's ineffective leadership.

Historical data supports the claim that Yuanheng's reign was marked by political instability. For instance, during his reign, there were numerous uprisings and rebellions, both internally and externally. The Song Dynasty's military campaigns were also largely unsuccessful, leading to a loss of territories and a weakened empire. According to the "Zizhi Tongjian," a comprehensive history of the Song Dynasty, during Yuanheng's reign, the Song Dynasty lost control over the region of Shandong to the Jin Dynasty, which was a significant blow to the empire's power.

In conclusion, the Song Dynasty avoided Yuanheng due to his ineffective leadership, which led to political instability, corruption, and military defeats. The consequences of his reign were severe, resulting in the loss of territories and the eventual fall of the Northern Song Dynasty. Historical records and data provide a clear picture of the challenges faced by the Song Dynasty during Yuanheng's reign, highlighting the importance of strong leadership and effective governance in maintaining a stable and prosperous empire.