> If you had a computer that only booted, or a car that only started, 40% of the time - you wouldn't say, well.. the system is ok - sometimes it works out!

This is an unfair comparison because the standard for a marriage succeeding is a lot higher than for computers or cars. If I bought a car or a computer and it and had only a 60% chance of failing to last until I'm 80 years old I'd consider that fantastic.

But a marriage that fails after ten years is counted as part of the 40% failure rate.