It's often hard for a manager to judge how productive a developer is being. Often they're insufficiently qualified to judge the standard of the code being prod

It's often hard for a manager to judge how productive a developer is being. Often they're insufficiently qualified to judge the standard of the code being produced or whether one solution is more elegant/reusable than another, and instead are just using heuristics which work for other types of employment, such as estimating how much overall time and effort was put in.