If you read any biographies of that era, one of the things that stands out is the amount of time Lincoln and others spent on 'patronage'. Most of this day, especially early on, was spent talking people who wanted to be postmaster, inspector, etc. One even sneaked into Lincoln's wake to talk to Johnson. When asked if he realized he what was going on, the office seeker said something like, 'the matter I wish to speak with you about is especially important'. So I see why they have this law. There are still a lot of people who see the gov as a giant cash cow.