Yes, exactly. It is a defence, in the sense that it allows businesses to engage in harmful mergers if there are sufficient economies of scale arising from them. The problem with this mechanism is that it puts the burden on consumers. We give these businesses a free pass to undermine competition in the hope that maybe they will be able to compete better internationally, but it's consumers who are paying the price for that.
It raises the question of politics and the political nature of competition policy, which gets swept under the rug when it comes to conversations in Canada.