If you actually care to check you will see that the free seating has worked well and been cost effective.
A number of issues have driven the change of policy, particularly the intenational flying and the reduction in the cost over the last two years of allocating seats. There will still however be an increase in cost which most likely will end up being past on to the consumer.
I believe it is a good policy change in the light of a number of changes in the Company's direction.