I think it's beautiful when both parties understand the true commitment involved, maturity necessary, and the importance of effective communication, and also the importance of regulating ones own emotions (taking responsibility for how you feel and not blaming another person for it).
I think most marriages fail (outside of missing fundamental elements) because people are either selfish, have unrealistic expectations, and are immature and want things their way without compromise and/or sacrifice. I do not believe in a person having to sacrifice who they are, their dignity, integrity, self respect, etc just to be with another. And if those things are ever being called into question, that person needs to value themselves more than their spouse.
Also, marriage cannot be the same for each couple, and people need to figure out what they want and expect from it so they don't go in thinking some off the wall shyt that may not work or be the best fit.
That's how I chuck it