Edit: A comment further down points out that only 18 of the 324 positions are symmetrical, so the vast majority of Chess324 positions could not happen in 960.
Secondly, at other levels one of the most important things is always whether a player can show enough sustained technique to convert some advantage and there’s always a chance for the person who is behind to swindle some draw if the guy who’s ahead can’t do this. This sort of a change would make that conversion technique somewhat irrelevant. The person ahead could just turtle up and guarantee themselves a win.
I know for a lot of people having draws in a game is very unsatisfying to some spectators[1], but the existence of draws in a game changes the strategy a lot meaning a player who is ahead has to press their advantage in order to secure the win and not allow a late heroic rearguard defence to secure a draw. That is (in my view) generally good for the game.
[1] I am a big fan of cricket and this is a common criticism of the game from folks who don’t like it.