It's obviously not about winning and losing. Both Nagi and Ruka say they need Hayate, but that's not exactly the case. Neither one of them thinks how Hayate feels and neither does Hayate - which is pretty much the whole manga summed up in one line. Except the Athena arc which completely reversed that (it was all about how Hayate feels, what he thinks, what he wants), which is probably why it was so exceptionally good.
Anyway - Ruka has a burden of her parents' debt and is full of conflicted feelings about her career. Nagi is a hopeless lazy bum, who struggles to overcome this now - which became much more pressing an issue ever since she lost her mansion and luxury. Basically this competition is an excuse for character development and whoever wins or loses in the end, they will both (hopefully) benefit from it greatly.
Now, what interests me is Hayate's development. He's obviously involved and with Ruka's trauma being the exact same as his, this would be a fantastic opportunity to have him develop also. Tackle the fact that he might be lying to himself about being truly happy with just working off the debt at Nagi's place, just like Ruka wasn't entirely honest with herself about her motives for moving on with the idol career. She just realized she would most likely quit had it not been for the debt and thus that she is NOT happy and might never be. That's harsh - and it might be just as bad or worse for Hayate.
You know. Gag manga.