Just as many people decide to get married, many later decide that they made the wrong choice. About 50 per cent of married couples end up getting divorced, and since the Canada Divorce Act, couples haven't required a reason to get a divorce -- they merely need to show that they have been living apart for more than a year.
In England, things aren't so clear. Sir Nicholas Wall, the most senior family law judge in England and Wales, advocated for no-fault divorce in 1996, but Tony Blair's government rejected the amendment, claiming it would make divorce too easy. Wall is once again advocating for no-fault divorces to be the norm.
While it is bad enough that the state tells us who we can't marry, it's an additional injustice when they also set the terms for ending marriage. Such laws are unjust because in a liberal society citizens, not the state, should be in charge of deciding their own values.
There are beliefs that all members of a democratic society must hold, like that killing adult humans for profit is wrong, but there is plenty of room for variation regarding other values -- what god (if any) in which to believe, what sex of partner with whom to spend one's life, and many others.
A further problem, which is the justification Wall provides, is that showing fault in a divorce necessarily means that one person is to blame. This isn't, of course, always the case. Two reasonable people can mutually decide -- just like they did when they got married -- that they no longer want to spend their lives together.
Divorce need not be a zero-sum game. It can be to the mutual benefit of both parties, and to demand that it must be otherwise is to demand blame when none exists. To amend an old saying, "It takes two to get married and divorced." There's nothing wrong with doing either.