Just like the housing bubble

Glenn Reynolds: The higher ed bubble is bursting. It's "an overpriced good, propped by cheap government-subsidized credit, luring borrowers and lenders alike into a potentially disastrous mess."

This is a simple case of inflation: When you artificially pump up the supply of something (whether it's currency or diplomas), the value drops. The reason why a bachelor's degree on its own no longer conveys intelligence and capability is that the government decided that as many people as possible should have bachelor's degrees.