>When a fork *is* contentious, and miners, following economic incentive, end up choosing different rulesets to support different bitcoin users, then the chain genuinely forks into two histories.

This is only true if the soft fork chain has the *minority* of hash power.

If and when the soft fork chain has the *majority*, the minority non-soft fork chain will be re-orged away, and there will be no (lasting) split.