Why might a wine glass survive a fall on a carpeted floor but not concrete?

The impact of a wine glass falling on a carpeted floor typically does not produce enough force to break the glass. The same impact on a concrete floor produces a much greater force.

Due to the soft composition of the carpet, the speed of the falling wine glass is slowed before it actually stops falling. This buffering effect that slows the fall also reduces the force on the glass, reducing the likelihood that it breaks. Conversely, concrete has no buffering effect at all, so the falling wine glass is not slowed before stopping; this increases the force of impact and causes the glass to break.