Imam Intervention

If they had seen a marriage counselor also , the result might have been different . Marriage counselors get to the root cause of the problem and offer practical advice.
Yes marriage counseling does not work in all the case but in the majority of cases. (For support of this argument click here)

I am not opposed to going to Imam , they can instill Islamic wisdom into both parties , but issue can be deep rooted then not following the tenants of Islam for married life.
I am opposed to going to Just the imam and not exploring other options.