The trick is to introduce accountability. Maybe if we combined express with tourny - a player will be less likely to suicide if it sets them back a couple of resets. Or you can introduce accountability by forcing players to maintain the same country name from reset to reset.

Short of these changes, if you want to change the culture, you need enforce the cultural shift. Get a few grabbist buddies and kill off anyone who retaliates to land grabs with anything but another land grab. Do it enough, and the people who don't play the way you want them to will either change or leave.