Re: If you have to mention just one reason....
I think the only reason is incompatability. This can be due to any number of factors but really when its all boiled down, its just that - the inability of the couple to work as a team to acheive mutually desirable goals.
Lying to your spouse? You are NO team player, your marriage is not a partnership...
Money troubles? Work it out - together...maybe wife works for a while, maybe spouse gets a second job...
Interference from other family or even friends?....should make little differece if each partner knows the other well enough to lend a helping sense-of-humor or shoulder to cry on....
Lack of communication? One or both dont care enough about the relationship to allow it to flourish....
Mama's boys or Princess girlies?... both are apparently somewhat prevalent problem "types" in Desi culture. Mama's boys want slave wives who will wait on them and their parents. Princess girlies want a rich man to worship them in every way. Neither works. Ever. (that I know of anyway)
Arrogance? Nagging? Bitterness on either or both sides of the marriage?....there is no sense of partnership here. Different ideas, different ideals.
Different culture/religion?...if it comes to such a drastic step as to desire divorce, the issues were not considered prior to marriage. Even if the couple are of differing religions, it should NEVER come to divorce upon the birth of a child, arguing over what religion the child should become...its not like children are a surprise. PLAN. TALK. BEFORE marriage!
Every single one of these examples boil down to incompatability, whether due to lack of knowing each other prior to marriage or to immaturity or lack of readiness for the sanctity of marriage. Any one or more of these problems CAN be addressed and changed....IF BOTH partners participate and WANT them to change.
Please dont think that I'm being condescending here or that I'm critisizing divorce; I went thru one myself. Due to one or more of the reasons above which - yup - boiled down to incompatability.