The logical endgame of that approach is to have a big tug-of-war between two big coalitions struggling to steal stuff off the other (which, in fairness, is a pretty common equilibrium in democracies).
That actually goes right to the heart of the issue - you can't get a just society by doing things by the numbers. To get a just society, just policies need to be implemented. If the winning side of an election wants just policies then there will be a just society. Otherwise society will be injust. Participation doesn't change the dynamics of that at all - if anything it makes it harder because the majority is generally an unprincipled blob and certainly does not make time to reflect on matters of fairness (Australia is hardly a just society, simply that the people getting a bad deal are relatively small minorities, not actively mistreated and can be reasonably ignored). If we had a reliable process for achieving a just society we'd use that instead of democracy.