Hikaru Nakamura commented on Chess960 (or 'Freestyle' chess as chess.com is desperately trying to re-brand it) and said that as a 'spectator' sport he felt that only the high-elo crowd would really get excited about 960.

To clarify, not that lower ELO or the casual player wouldn't enjoy it but that there is so much history with the standard layout that even the beginner ends up understanding the high-level tactics and strategies of the openings.

This makes standard chess much more enjoyable for more people to watch and follow (i.e. bums-on-seats at the chess tournaments). While the super grandmasters are celebrities for the chess crowd in their own right, those lower down don't generate that kind of excitement and throwing 960 in the mix would see much less eyes than normal chess does.

Literally 960 different layouts might generate some types of opening theory, but to layman or perhaps 2200 and lower ELO players it just isn't that much fun to watch.

Tournament chess rules are typically laid out to promote fairness.

The only possible quibble is who starts with white --- which is typically chosen at random --- which is fair.