Why [isn't the analogy quite accurate]? A shoplifter might steal underwear, an employee a CD, and a fraudulent publisher a click. In each case, the business suffers a loss; in each case, some crooks will get caught and others will get away; and in each case, losses aren't enough to threaten the business model unless they exceed a manageable level.
It is not obvious that a given click is fraudulent. If there is a history of such clicks, they may be fraudulent. Whereas even if someone removes one item from the store, no matter how small or inexpensive, a crime has been committed.
Furthermore, as I said before, any business is subject to crimes, which are much more difficult to pull off than click fraud. However, not all businesses, even Internet businesses, are subject to click fraud. So the businesses that are subject to click fraud are more exposed to losses than those who aren't.