I think the key point here is that corporation using your data doesn't imply that their CEOs or high executives are personally looking at your activity.

On the other hand the fact that a specific person within those companies is not tracking your web activity doesn't make the privacy problem go away.

Nevertheless, I just find it silly when somebody just alludes that some actual person (e.g. Bill Gates, Sergey Brin) might actually track your specific searches; although I know nobody actually believes it, it's just a figure of speech, just to give a human body to our fears. That's the problem: corporation aren't humans, yet they have a life of their own.

EDIT: thanks to acheron for the name of the figure of speech I was mentioning. My point is that this personification is misleading and causes endless discussions about what can be expected by this or that company, and what you can expect from their employees etc.