There could be different ages of visitors that can affect alot.
1: itd just be cool and more realistic.
2: you can charge different for certain ages, changing the possibility of people joining the park. ( ex: charging less for seniors leading to more families joining )
3: new exhibits targeted towards certain ages.
4: different ages might enjoy certain exhibits more ( ages 16-24 would like the more iconic dinosaurs and petting zoos. Elders would like the more peaceful or slow dinosaurs, others would like everything else.
5: in addition to #4, you could also change the state of some exhibits. ( changing exhibits to the prime exhibit, etc. )