“Struggle” here refers to dealing with the inevitable difficulties and errors that occur when we’re engaged in learning something new to us. In the carpet/buzzer experiment Westerners tended to view the buzzer as an error to be avoided, whereas Easterners tended to view the buzzer more as an input for learning. Struggle is a sign that we’re engaged in learning, not necessarily something to be avoided. If we’re not struggling we’re probably not learning.
Presentation by Professor Jeffrey Liker at the 2015 Toyota Kata Summit.