Spot on. And many people don't realize that this films are fiction. That is, there are succesful woman who have love.
Here we would never see what happens with the characters later. We might very well imagine a life where Miranda finds a new love, maybe even another woman. Or Andy ends breaking up with Andy and resents missing on her career for him. Those kind of things happen in real life. But rarely are told in these movies. The "happily ever after" is appealing, but flawed.
That is why shows like "the good wife" have such a strong impact and appeal. Because they are the opposite. They show a much more nuanced reality.
It is a matter of time that romantic comedies evolve and show different types of love. I mean, now we are seeing succesful women with younger men in the real world. And many viewers are middle aged women with career. If romantic comedies are meant to be fantasy, then it follows that at some point we would see that women as the lead.
Maybe we should start a list of comedies that we have liked and don't follow this pattern.