The current debate on saying "sorry" to the "stolen generations" is based upon the fact that state and federal governments throughout the early-mid 20th century had the legal power to remove aboriginal children from their parents. This, of course, they did. Why? There is nothing to say that this was done because the people doing it were somehow evil scheming people. Certainly one of the core beliefs in Australian society was that the aboriginal people were dying out and the taking of children was a way to prevent this from happening because these kids were then placed in "proper" homes. In other words, the reason for the children being taken was because the people doing it were doing it in the best interests of the children involved.
Of course there are many instances of "good intentions" having unforeseen side effects. In hindsight, governments should not have been doing this. The emotional turmoil it caused families was immense. Moreover, it was a specific policy aimed at Indigenous Australians rather than the population in general. Comparing the work of, say, child protection officers today who take children from dangerous parents to what happened to aboriginal children throughout the 20th century is not sustainable.
Nevertheless, we need to remember that these children were taken out of best intentions - and that is important. After colonisation in the 18th century, diseases like smallpox and measles ran rampant through the aboriginal population for over a century without any effort on behalf of the white rulers to help. Although estimates obviously vary, the population of Indigenous Australians fell from a couple hundred thousand in 1788 to between 50 - 90 thousand by the 1920s.
It was, however, in the 1920s that things changed for indigenous Australians. Up until that point, the welfare of these people was ignored. While there were certainly events like massacres perpetrated by white colonists, the vast majority of indigenous Australians died as a result of malnutrition and disease. (Why malnutrition? Because aboriginal people were hunter-gatherers whose land had been appropriated by farmers and settlers, thus depriving them of their traditional source of food).
In the 1920s, governments around Australia decided to set up "reservations" for Indigenous Australians. Some of these were even farms that Aboriginal farmers ran at a profit (though white farmers were quick to close those ones down). Health care and education were provided to them as well. As a result of this - available food and health care - the aboriginal population began to increase again.
The policy of taking children away from their parents is part and parcel of the same policy that greatly reduced mortality rates and allowed Indigenous Australians to begin growing again. The current population of Indigenous Australians has, by some measure, surpassed that of those who were there in 1788.
Of course, this is not to say that an apology isn't required for the stolen generation - of course it is and I'm glad that it has finally happened. We need to remember, however, that some of the policies that our grandparents and great grandparents initiated - no matter how paternalistic or misguided - actually did work.