To marry out of love - is not possible; what's more, I would say that not a single person on the Earth married out of love. It sounds a bit unpleasant and dreadful. It turns out, that the thing almost every young person is hoping for, is impossible. To explain why this is so, and whether it's dreadful, we need to agree on some terms. Very often, people use the same words, in completely different contexts. That's why, primarily, I'll try to explain what I imply by the word "love."
One needs to elaborate on this. at this point, this is not a good argument. Granted, a lot of people do not marry for love, and even some of those grow into a healthy strong relationship. To claim that no two people marry out of love much less one, it a bold and highly unlikely hypothesis.