Revert "Default to enabling SDC columns"

This reverts commit 12fb01a.

singer_sdk/sinks/core.py

@@ -397,7 +397,7 @@ def include_sdc_metadata_properties(self) -> bool:
         Returns:
             True if metadata columns should be added.
         """
-        return self.config.get("add_record_metadata", True)
+        return self.config.get("add_record_metadata", False)
 
     @property
     def process_activate_version_messages(self) -> bool: