Stupidity. Apparently, they want to beef up (excuse the pun) their lunch and supper business. They thought having "pancakes" in their name was making people think they were strictly a breakfast place, and maybe it was. So by changing the P to B for "Burgers" (i.e., International House of Burgers), they are hoping people will start going there more for lunch and supper. Maybe some will, but I don't think it'll be nearly enough to make up for the loss in business resulting from the masses that think they no longer serve breakfast. Basically, I think they've just shot themselves in the foot by shooting their brand right in the head. It wouldn't surprise me if so-called "IHOB" goes belly up within the next year.
I mean, I understand wanting to expand their market by reaching a wider demographic, but that could've been done without betraying their brand. Doing that, that takes a special kind of idiocy, the kind that thinks letting go of a bird in the hand that you really don't have to let go of to chase after two birds flapping around in the bush is a good idea.