Well, that would be a failure of self-control or human nature not abstinence, wouldn't it? In the words of a great American, "abstinence works every time it's tried." The fact that it's not always tried is not the failure of abstinence.
But I can see where those who benefit from children not being encouraged to practice abstinence would want to shift the blame.
Considering that the success or failure of abstinence is ENTIRELY dependent on human nature, you cannot separate the two. I refute the naive notion that abstinence succeeds every time it's tried. There are of course instances in which abstinence is just thrown to the wind and not even attempted, but I'm not speaking of those.
Good people fail. Good people fall short. It's a fact of life. Many times, with young people especially, the will to abstain is present, but the flesh is weak. To think that just because a young man or woman attempts abstinence that success is guaranteed, is naive at best. As it has always been the way since the dawn of history, a certain number of young men and women with the best of intentions will still be finding themselves asking, "What was I thinking?" the morning after.