Especially with the JW mindset, marriage is sort of a thing that a young person can be tempted to shoehorn into their lives with the wrong person and far too soon, especially because it's the only way they feel they can experience sex.
The biggest problem I see with the whole JW dating life is that typically you do NOT end up dating multiple people, and therefore you don't learn about yourself and what you actually like in the opposite sex. When a JW starts dating, their hormones take over all brain activity. They're not allowed to masturbate, and not allowed to be remotely physical with each other unless they're contemplating marriage. Logic goes out the window, hormones run rampant, and each of them goes home with wet underwear. Then they're not supposed to masturbate to relieve the sexual tension. They feel guilty for doing that and their only way to relieve the sexual tension is to marry that person ASAP.
On another sad topic, whenever my niece decides to tie the knot, I won't be attending the wedding. I swore to myself that I would NOT enter another Kingdom Hall for any purpose. Not only that, each of the parties in the marriage are supposed to put Jehovah first. They're not supposed to truly love each other and are conditioned to judge each other's actions.