My only suggestion would be that you are paying a team of workers to maintain the building but due to there being so few people and such a big city to maintain in addition to the recruitment center they are working on, they just do not get around to doing it.
I kind of envision each city/town/region having a pool of individuals capable of doing this kind of maintenance work. These people are responsible for maintaining roads, residences, places of business, recruitment centers, smithies and all that. The simple fact it that by default these little worker bees are scrambling to accomplish 100 tasks with only enough time to complete 20 of them. By paying them to care for our recruitment centers we are simply adding more to their list.
The thing is we can not prioritize things for them. We can not say "Keep these 10 blocks in good repair for yourselves, take care of all noble and governmental establishments and all recruitment centers and buildings and such. Let the rest be. We know that will make it difficult for new immigrant to establish themselves, just do as you are told." It does suck but I kind of get it.
On the flip side one could look it as saying "I pay an initial lump of money for materials and manpower to build a structure. Once built I pay maintenance fees. Theses fees provide the materials for repairs and fund a dedicated work force that takes care of all upkeep for this structure." This could work and could provide justification for allowing recruitment centers to keep kicking when the population is very low. The mechanics of the game, however, do not seem to support this view.
