The guy is making a point here.
Do not add to your employer's assets unless you are expressly instructed to.
Quite simply, don't write any software to improve your employer's operations unless you are instructed by your boss to do so. Don't use your own initiative to do something unless it is acknowledged and approved by your superiors.
Factory workers don't go about fixing broken equipment on the assembly line. The equipment manufacturer's service employees are the ones who do it. Trust me, those guys won't touch any piece of equipment until they are instructed to do so in writing from the customer or from their managers.
Software and engineering guys are only to happy to write stuff for their employees and even sign agreements not to develop their own software even when it isn't done on company time.