It's been this way for at least thirty years, as everyone who has gone to graduate school since the 1970s has always known before going into a Ph. D. program, but that doesn't make the situation good. It's been the same for several decades and despite occasional spasms of hope ("Urgent need for more Ph.D.'s in English predicted, studies say"--remember those headlines?), the employment situation doesn't seem to be changing.
There was a time, though, when the situation wasn't like this, as I've heard from older colleagues, so I thought a glimpse of those times might be interesting--or maybe would call them into being again.
Let's hope those days aren't gone for good.