(Literally blight is a kind of fungus or rot that affects farmers' crops such as grain or vegetables.)
here is no good as a way to cut. After Black shouldn't continue.
In this common joseki, is left next to strong black stones, and so is blighted. Losing this stone is the price white pays for making territory on the top side. In this case, is not a mistake. This is joseki.
More information here.
 If you blight an opponent's stone, are you a blighter? ;-)