Ambition can have a negative connotation, perhaps did so even more during the time of Shakespeare. The word ambition comes from Middle English “ambicioun”, excessive desire for honor, power, or wealth†.

Just think of examples where people perform virtuous acts on the pretext of wanting to do something virtuous, but in reality for selfish ulterior motives.

* Politicians fighting for a cause they could not care less about, but will take it up if it helps to get them elected.

* People you have known for a long time but never gave a damn about you, yet suddenly they begin to act nicely. Later you discover they acted kindly in order to get something from you they needed.