Both are crimes, one is far, far more significant (as your link describes).
Shoplifting is a crime. But it is a crime done by those who have been systemically abused. In a more just world shoplifting would be so insignificant to anyone that it would be hardly discussed. (Because people's needs would be better met in a more just world)
If shoplifting were as serious a problem for owners as wage theft is for workers, then the massive disparity of wealth between the two would not be continuing.