The fact that WT ties the hands of an abused mate with the qualifier "extreme" is intrusive at best. In practice, this qualifier makes it very difficult for an abused person to leave the relationship, as at the very least the person leaving will be judged, and often they are shunned or disciplined by the elders for not following "scriptural" guidelines. Note the liberal use of qualifying terms WT uses:
*** lv pp. 220-221 The Bible’s View on Divorce and Separation ***
In certain extreme situations, some Christians have decided to separate from or divorce a marriage mate even though that one has not committed fornication. In such a case, the Bible stipulates that the departing one “remain unmarried or else make up again.” (1 Corinthians 7:11) Such a Christian is not free to pursue a third party with a view to remarriage. (Matthew 5:32) Consider here a few exceptional situations that some have viewed as a basis for separation.
Willful nonsupport.
A family may become destitute, lacking the basic essentials of life, because the husband fails to provide for them, although being able to do so. The Bible states: “If anyone does not provide for . . . members of his household, he has disowned the faith and is worse than a person without faith.” (1 Timothy 5:8) If such a man refuses to change his ways, the wife would have to decide whether she needs to protect her welfare and that of her children by obtaining a legal separation. Of course, Christian elders should give careful consideration to an accusation that a Christian refuses to support his family. Refusal to care for one’s family may result in disfellowshipping.
Extreme physical abuse.
An abusive spouse may act so violently that the abused mate’s health and even life are in danger..."
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This leaves it open that if a mate is suffering "only" minor physical/mental abuse, they are not free, under WT rules, to divorce/separate without suffering some discipline.
The other result is that, in WT's eyes, the person is not free to remarry if they separate/divorce for anything other than adultery, which means, if they desire to remain a JW in "good standing", it is likely they'll never enjoy a meaningful relationship in their life with a person of the opposite sex....ever.