Its meant to have a random match with little to no preparation. Nowadays with computer preparation getting better and better, most masters need to memorize a bunch of sequences of moves with lots of ramifications to have a good openning and good game. Which made the game a lot about memory rather than other skills that were originally challenged in the game.

This way, making the initial piece placement random, you kinda throw out the window all the preparation masters have and so they have a game kinda like the old times, challenging skills like originality, tactical vision, initiave, awareness, etc and not so much memory.