Inheriting a kingdom brings a critical choice: a new ruler can either correct the failures of the past or simply accept them. In this case, the new king chooses to continue the spiritual missteps of his predecessors rather than look to the righteous founder of his royal line for guidance.
Rather than inventing new ways to do wrong, his primary failure lies in his passivity. He completely accepts the broken spiritual reality that was already in place before he took the throne. He makes no effort to fight or abolish the worship at the high places established by his father, whether those sites were used for outright idolatry or for the improper worship of God [מלבי״ם, ביאור שטיינזלץ].
This passive acceptance stands in sharp contrast to the legacy of King David. The new king traces his lineage back to David through both of his parents—his father is David’s grandson, and his mother is the granddaughter of David’s son. Yet, despite this deep royal pedigree, he inherits none of his great ancestor's faith or moral integrity. Instead, he adopts only the negative traits of his immediate parents, such as pride, foolishness, and a tolerance for idolatry [אברבנאל]. His heart is not fully devoted because he lacks the absolute, unwavering dedication to God that characterized David, a dedication absolutely necessary to uproot deeply ingrained sins [מלבי״ם].
This spiritual failure is especially tragic given the grace God extends to his family. It is solely due to David’s past merit that God allows the dynasty to continue ruling in Jerusalem. This ongoing survival of the royal line is compared to plowed land that reliably produces fruit. However, even with this continuous divine favor protecting his reign, the king still chooses to turn away from the righteous path set by the father of his dynasty [אברבנאל].