Bane - engage your brain please.
The marry only in the Lord section of scripture is prefaced by Paul saying twice, once in verse 12 "to the rest I say, I NOT the Lord...", and once in verse 25 "I have no command from the Lord". So Paul explicitly says this passage is his personal judgement based on his life.
The Society then takes the self confessed uninspired opinion of a confirmed batchelor and works up a watchtower talmud of procedures about a sister marrying a non-JW - she is to be marked, her family may lose their 'priveledges' if they attend the wedding.
What I think we all can agree on is that the Bible - Paul himself, apparently, says in 1 Timothy 4 that "forbidding to marry" is a "teaching of demons". Incidentally he says this is what "the Spirit says".
When you consider the ratio of women/men in the society is about 60/40, this means the society is de facto forbidding to marry 2 sisters in every 10 - not even allowing for the brothers who "stay single for the lord". Of 7 million witnesses this equaltes to about 840,000 women who have no chance of finding a "witness mate". Even if only half of those want to get married, that's almost half a million women denied a marriage relationship - if they follow the direction of a self-appointed religious organisation who have codified the 2000 year old personal opinion of a pharisaic single man.
Nb - Doesn't the Bible indicate God once saved his people by a believer marrying a pagan? Remember Esther?