Hi Brock - you are spot on. If people are getting married to the wrong partners then you have to ask why and the pressure to conform to the WTS view of morals and who might make a good marriage partner are critical factors in this, as your post describes.
The slight irony in this is that you could argue from an objective perspective that the WTS advice on dating actually does carry some sensible advice. Ignoring the views on sexual conduct and the "spiritual qualifications" then much of what is left of what the WTS says could be decent, secular advice such as discouraging rushing into a relationship, doing so at a young age, ignoring the warning signs of a poor relationship, papering over severely bad personality traits, looking only at physical attractiveness, developing good communication patterns etc.
The problem for the WTS is that all of this "good" advice gets swamped by fact that the majority of the young people it is aimed at are hormones on sticks, have no other outlet for their feelings other than pursuing them and do not have other things to focus their attention on such as getting a good education.
I don't think it is breaking news that choosing the right life partner whatever your beliefs is not an exact science. I have no doubt that the circumstances peculiar to Jehovah's Witnesses adds yet more complexity to this. All the issues and factors you mention have as much resonance now as they would have done 20 or 40 years ago. When I look at the marriages I know that have failed then the culture of dating in the WTS has contributed to people getting married that otherwise almost certainly would not have done. Naturally the problems in the physical, emotional and personal aspects of the relationship are all intertwined but going on the numerous breakups I have witnessed over the years, I cannot point at one where more pre-marital sex or what has (or has not) gone on in the bedroom could really be said to be at the heart of matter.
At the end of the day, however, what you posted is absolutely food for thought and I really hope that there are young people who read it and take notice of the massive impact that looking for love inside the constraints of a WT courtship could have.