Sounds like one of those old share purchase plans from the 90's. With those, the new shares didn't add to the cost base for CGT purposes either.
For fully franked dividends, it's obviously not worthwhile if your marginal tax rate is equal to or less than the corporate rate. If it's more, then it's debatable at best with the question being how much CGT you pay when you sell. That's obviously hard to know so I would only consider these plans worthwhile for unfranked dividends unless your mix of tax and income support has you in a particularly high EMTR.