One more reason, they have choice, They are seeing a way out, they have believe they can go through it. So let it be, this is not 19th century, divorce might a big issue for Muslims families, but in west its very common or easily move able.
Slow acceptance of divorce is a blessing and a curse. it's a true blessing for those who are stuck in truly horrible situations with no other way out.. but at the same time, if ppl have stuck in the back of their minds "there's a way out", that might prevent them from putting their all into the relationship. Honestly I think it's better this way..that there's a choice. After that its' up to the individuals to work as hard as they can towards preserving their marriage