Purely my opinion - but i think it's nothing more than a glossy soap and so would've fit perfectly into daytime telly.
That might well be true, but it would never have achieved the same ratings as it has in its prime time slot. It would have been a waste if it aired solely in daytime, when most people are at work. Plus, if it did relatively well in daytime, chances are it would have moved to prime time eventually, just like Weakest Link, Deal or No Deal etc.