We are in a mid-term election. If you congress will oppose the executive, there will be no progress, no unpopular law will pass. I never really liked the term opposition and more putting genuine before it. It just suggest defiance and, no secret, oppose. Can't they think of any other term? More like Democrat and Republican.
I agree that having an opposition in the government would mean less progress, if there is any progress at all. However, this is one way we can have check and balance within the congress itself, aside from the other branches of the government (Executive and Judiciary). If there is no opposition anywhere in the governement, then we might as well have tyranny or dictatorship. We have to give up something to gain another.
Unfortunately, the reason why there is much more regression than expected is because most, if not all, of the elected politicians have their vested interests as their priorities. These special interests hinders them from passing the laws that are good for the country, or at least their districts, by passing and pushing for laws which will benefit the said interests instead.
Now, on changing the name to something like Democrat and Republican, this is too much colonial mentality. But that's beside the point. The point is, regardless of how people will call it, it is still the opposition in its core. Nothing will change that. That is why you call it democracy in the first place....