The hardcore players that want it off are also the players that are going to actually be aware of the setting and know they CAN turn it off. It should be on by default for those who don't even know it's a setting
Personally, I wouldn't call people who simply don't want to use a system that back-handedly calls them a cheater, or who just don't want to play with the game rigged in their favour, 'hardcore players'. I'd call them pretty regular average players.
I wouldn't call players who take a moment to look at the game's options screen before diving in 'hardcore players' either. I'd call that pretty average normal behaviour for most pretty average normal people.
Personally, I'd consider that players who actively want the game to bend over backwards in order to cheat on their behalf and ensure they win, and players who find the concept of taking a glance at the options screen to be too much effort, to be the outliers in this scenario.