Years ago, someone asked Jay Leno why he would do
Doritos commercials, but not beer commercials. He responded that "you don't see people splattered all over the road because they ate too many Doritos".
Now, long term effects of eating too many Doritos aside, I've come to the conclusion that some people have a very hard time differentiating the actual consequences of certain acts and actions. Sure, pornography is bad and many people let it get out of hand [no pun intended], but to say that it is the "scourge" prophesied in D&C 45 might be taking it a little too far.
In fact, the internet could be looked at as almost a great experiment to see what happens to a civilization that becomes totally steeped in pornography. Based on what I've seen and heard from teenagers today, we are only a few generations away from pornography becoming totally available, discreetly and on demand to everyone over the age of 8 (and we could arguably already be there). So we don't need to argue over hypotheticals and forecasts. We just need to observe, and take stock of what has really happened to our civilization.
I would expect that we would find a population-wide trend of some people becoming addicted to pornography (unable to control their compulsion to constantly watch it, and becoming dangerous and destructive as a result), while the vast majority have a "casual interest" or no interest at all. If we include anyone who ever looks at pornography in our definition of "scourge", then it may be accurate. But if we only include those who have a destructive compulsion, it might be a smaller trend and not up to the demands of the "prophecy".