Krishna arranges everything in this material world in the most wonderful manner that it reflects the spiritual world but at the same time accommodates people who are not in the consciousness of the spiritual world. So people with similar mentalities and proclivities are placed in similar situations (in a varnasrama society).
Lecture on SB 3.6.32 – About the Four Varnas – Vyasa Puja 2008 – 5th Jan'08 – Tirupati