Things like these can happen with any service provider. The key difference is that no other company has so many popular services linked together. Using Google this way basically means putting all one's eggs in one basket. We all know it's an unwise thing to do. An yet, people do it every day, for convenience.
Personally, I set up separate Gmail accounts for their different services. First, I don't want them to profile me automatically (they do it through correlation anyway, but let's not make it too easy), and second, in situations like these, only some of the eggs are broken.