Or: the "weak spot" might simply be that people inherently differ in their display preferences. _I_ happen to like Google's clean design, but if even 5% of the population actively dislikes it, someone could make some money. Google's "weakness" then becomes the fact that they can only present one face to the world. The beauty of this approach is that it will be tricky for Google to counterattack since they won't want to confuse their brand.
In short, Google may not have weaknesses, but their market does.
I wonder if African-American slaves would agree. Or West Europeans, especially those in concentration camps. Or South Koreans.