Why is transpiration called as " necessary evil "?

Explanation

1. Transpiration leads to loss of water , 95% of absorbed water is lost in transpiration.
2. It seems to be an evil process to plants . However number of process like absorption of water ascent of sap and mineral absorption directly rely on the transpiration.
3. Moreover plants withstand against scorching sunlight due to transpiration. Hence the transpiration is a " necessary evil " as stated by Curtis .