Where I am coming from is that I can see a case for a DD with actively managed funds, there will be active trading and if the fund manager is doing his job properly and plenty of gains.But, to be clear, this isn't a special rule for passively-managed funds (either in the US or in Australia). The same system is in place for actively-managed funds. Honestly, I can't see any good argument for having different tax reporting/collection mechanisms for active and passive funds.
DD for passive trackers and especially distributing ones (they exist, I have a couple) is excessive.