Most IFB congregations are so small that singles are not ever going to meet a suitable mate within their own congregation. If they visit around to other churches, even of like faith and practice, to look for a mate, that is sometimes frowned upon as evidence of disloyalty to one's own church and MOG. So it might make a certain amount of good sense to enroll in an IFB college in hopes of matrimony, and I have no problem with young people who do that - it may better than letting the movement die out because the young folks are not marrying and reproducing.
But the problem is, if the students are not regarded as loyal enough to the administration, then they are discouraged from dating and mating, and engagements are sometimes deliberately broken up by the administration. James Spurgeon encountered that problem at Bob Gray's college as recorded in his "Tales From the Temple" book. It is my understanding that insufficiently loyal students at Bob Jones University are "socialed" (forbidden to date). Back when I was being pressured to enroll at BJU, one of the enticements was that if I went there, I was absolutely guaranteed to find a wife there. I didn't believe it, and I didn't go.
I totally agree that "A Bible college is a pretty expensive dating service." In theory, it would be better for church people to let their young people stay at home and then do some matchmaking (with permission given to do so by the objects of matchmaking) to help them find a mate close at hand, as opposed to imposing upon them sell all, uproot themselves, disrupt their lives, leave family and church friends, and move across country to a Bible college from which, in most cases, they never come back to the "feeder churches" that sent them there. (And in many cases they don't find a spouse there anyhow).
A lot of already-married Christians do not see any need for matchmaking and they even think it is unspiritual for singles to want to escape their low-caste status (as assigned to them by Bill Gothard and his "chain of command" principles for never-married singles) by getting married. So, I am totally sympathetic to young women, and young men, who attend Christian college partly with the motivation of finding a mate there, as long as they weren't arm-twisted to go, like I was pressured to go to BJU. But please don't go to a college run by sex perverts like North Florida Baptist College.