Clearly, I don't know every situation, but I suspect that for every couple who met and married within a few weeks and remained married until death, there are dozens if not hundreds of couples who took a similar amount of time and later divorced.
That aside, I have my own experience to draw on. I got married less than eight months after meeting the woman who is now my ex-wife. There were certain key things I didn't know, and things I did know but didn't investigate adequately, which contributed to the eventual divorce. Mea culpa, et caveat emptor.
Many couples spend their "dating" time in a fantasy world, not investing time in preparing to be married. By all means, enjoy time together; dating shouldn't be a series of grueling interviews either. It should be a time during which the idea of marriage is held very lightly, such that either party may say, "This doesn't work for me," without resulting in resentment or regret. Better to part peacefully prior to marriage than sadly after it.
Once engaged, many couples spend more effort and time on the wedding than on the marriage which follows it. A good pre-marital counseling process ideally should be the basis for several soul-baring conversations, but not the sum of them!
Some will argue that biblical marriages didn't have all this preparation, and that's true, but the culture in which those marriages took place is not the 21st century, in which fornication is celebrated, divorce is easy, and families broken by it are more common than intact ones. Frankly, we should be better prepared without all this work, simply by the acute awareness that marital breakdown is so common.