No fault divorce was looked on as a solution to several problems.
One was that often the grounds recognized before it became law were generally limited to cruelty or adultery, and judges knew that they were seeing people in court who had neither of those grounds; they just did not want to be married any more. The result was that people were perjuring themselves in order to get a divorce, often when both parties wanted the divorce.
Another issue was that requiring proof of either adultery or cruelty often put people, who might have that issue in play in the marriage, in the very difficult position of having to pay for a very expensive process; no fault did not require those proofs and so in many cases, the cost of the divorce would be much less.
A third issue was the opinion within the communities of sociology and psychology that children growing up in a family under great stress because one or both parties no longer wanted to be married would be far better off if the divorce occurred and the stress relieved.
Most people in favor of no fault divorce did not anticipate the huge increase in the numbers of divorce.
Many of the proponents of no fault divorce were basically secularists; that is, they did not see marriage as something God-given, or as sacramental, but rather viewed it as a contract. They did not see that the State had either a duty or a benefit to upholding the sanctity of marriage. Neither did they foresee the results of so much divorce.
Sociologists and psychologists, after much time, have been able to see (and actually say) that the results of their studies showed that children were much better off in a two parent family than being in a divorced situation. One of the surprises to the research was how many children as adults were still trying to deal with the psychological damage of having lost a two parent home (See the research by Judith Wallerstein).
And, as usual, there are always exceptions.