Bruce has written about this topic in the past, and as he mentioned in his blog, he was on the ESPN OTL Oversigning piece last year providing insight as to why oversigning is unethical and why coaches do it.
He was asked about it again recently in his mailbag on his blog and had this to say:
From @RowlffDogg Why doesn't the national media pay any attention to the practice of oversigning?
I've actually written about the subject several times and helped on a recent "Outside the Lines" segment on the issue. I was also the commentator discussing it in detail right after the near-10 minute piece aired.
One of the points I brought up on the show was about the practice of schools rewarding coaches with bonuses for signing a "top" class (either top 5, top 10 or top 25), or for landing a certain number of four-star players. With coaches having even more of an incentive to meet certain quotas and rankings, they often try to sign certain recruits that they know might have a very tough time qualifying academically.
I wrote about the "Sign-and-Place" method in "Meat Market," and for schools that deal heavily with junior college recruits, that also factors in. The process is this: Sign the shaky four-star prospect so that you can up your recruiting ranking, impress other prospective recruits, appease your fan base (and, in turn, the administration), increase your own chance of landing that recruiting bonus, and then send the players who can't get in academically to a junior college as if it's a farm system. If the kid turns out to be a complete knucklehead or flops on the field, you forget about him. If not, you didn't take up a spot for two years and then the juco coach, who is thrilled you sent him a talented player, has protected him for you and sends you back a more ready-to-play, developed prospect.
The rest is behind a paywall, so if you are an ESPN Insider (don't we all want to be?? haha) you can get the rest of his take on the topic. For those of you who have taken the position that there is nothing unethical about oversigning, perhaps this will change your mind.