The maintenance/findBadBlobs.php script requires cleanupTable.inc rather than Maintenance.php. Unlike several other maintenance scripts that include cleanupTable.inc, the FindBadBlobs class does not derive from TableCleanup, and does not otherwise reference anything from cleanupTable.inc. Likely this is either a cut-and-paste error, or a leftover from initial development that ended up going a different direction.
Because cleanupTable.inc requires Maintenance.php, everything still works. But including cleanupTable.inc gives the incorrect impression that findBadBlobs.php uses something from it, and is ever-so-slightly less efficient.
The simple fix is to change the require to bring in Maintenance.php instead.