There is an advantage in the minister's being required to publicly explain his or her decision. That transparency in and of itself will force the minister and his public servants to look carefully at what they're doing in justifying these decisions. I would have been interested, for example, in seeing the current minister justify the decision in the case of Potash, and he was spared that difficult task.
I'm convinced that the minister made the opposite decision before the Prime Minister's Office changed his mind. He had to convince his officials that all the work they had done should be turned upside down. It would have been an interesting exercise, and I would like to have seen the results.
But the real point to make is this: it is good public policy to narrow the scope for discretion. The more discretion a minister has, the more opportunity there is for political finagling. So I think it is in the interest of government and politicians alike to have a narrowly conceived area of discretion rather than a vague and wide one. If it's vague and wide, it is hard to deal with lobbying efforts.