I'm fairly young and one of my main wishes in life is to get married and stay married.
As for the topic, while I personally would and never have asked a girl out online much less propose marragie online, different strokes for different folks. They are obviously perfectly comfortable doing it so why not? And as for whether she is making the correct decision - she may not be, but who are we to tell her that. Suggest, perhaps, but not demand. They're not going to listen anyway. It's like when you tell someone not to buy Bose - you go over their house the next day and see a Lifestyle system in their living room.
And by the way, as for what that guy said love is, while I wish him the best, he forgot something huge which his marraige will not last without - love is also a commitment and a decision. Not just a feeling which will be there sometimes and won't be there sometimes (which happens in all lengthy relationships).