I think you could argue this point based on colonization in general, not just that of Australia. Colonization of such a distant and large colony could be said to be a bit foolish on the part of the British, but given that it was for location and as a penal colony, not as one for resources where the British had to have absolute physical control of all of the territory, I don't think it was their most foolish choice of colony.
I would agree that the colonization was a good idea, but the way in which it was achieved left something to be desired. Not only were the prisoners subjected to harsh, sometime inhuman treatment, but some of them were not criminals they were simply political prisoners.
It seems pretty hard to argue with the long term results. Australia is a thriving country today, which seems to argue that it was a good decision.
Now, in terms of how the actual colonization was carried out at the time, the planning seems to have been lacking. People were sent out with no knowledge of what they were getting into -- the Botany Bay site was not even suitable for the first colony.
Some of the early problems may not have been due to it being a poor decision, though. A lot of them, I think, were due to the brutal nature of the system that was imposed on the prisoners once they got to Australia.
Colonization was a way forcountries to gain new territory, new resources, and new capital. For good and bad, this brought the world closer together, removed its isolation and brought it into the fold of the world. Even if England did not colonize Australia, another country would have done it sooner or later.
The way the world population and the geographical areas occupied by humans has expanded, it would have been impossible to keep Australia isolated from the world for very long even without its colonization by people from England. Because of this I do not see anything wrong in the basic decision to colonization.
However how the colonization was done is definitely open to criticism. I think the treatment given to the local inhabitants was unnecessarily harsh, which did not do any good to any one in the long term.