I can think of two examples here in Chicagoland that have earned this distinction by being changed from their original configuration.
At Olympia Fields South, number 5 used to be a dogleg right three-wood wedge sort of hole, with a diabolical green with big right to left tilt created from the natural lie of the land. When the course got rerouted fifty or so years ago, it became a par-3 hole about 160 yards in length. Let's call it a six-iron into the green. That is not so bad, as compared to a wedge back in the day, but when the course was renovated by Steve Smyers a few years back, it got even longer so that the usual blue tee is 195 and the tips go back to 235 or thereabouts. In my judgment, that converts a hole that used to be a great hole into a mediocre hole, even though the original green is and was great.
Similar story at Flossmoor, the #3 hole, which used to be a par-5 hole. The creek was in play on the second shot, but it was manageably carried, leaving a player with a 9-iron or wedge into a severely canted right to left green built into a natural plateau. Now, the hole has been shortened to a par-4, with the creek decidedly in play which often leaves a four-iron or more into that very severe green. The hole is not nearly as good as it was, because, in my judgment, the hole was not designed for such a long approach shot. Now it's punitive and not as fun and, therefore, not as great. Mediocre is probably harsh, but the hole has been lessened, IMHO.