Why is “ we just grew apart” or “because I wanted to” not a good enough reason for divorce it seems?

Before marriage, the fun is falling in love, dating, and the crazy wild intimacy. After marriage its a challenge for both partners to make it work with each wanting what they want but also wanting a happy spouse. Communicating everything is harder than it sounds, but for those that can do it, marriage is bliss. For those that dont, they just grown apart.