The answer is that Klal Yisrael were in a terrible eis tzarah at that time. To escape the terrible gezirah they needed the sort of tefila described above. For although they were already davening fervently for a yeshua, they also knew that their leader was a “member of parliament” and would surely “look after them”.
Mordechai knew that this attitude was poison, therefore he went out of his way to show the people that he could not be relied upon. On the contrary, he specially antagonized Haman rather than acting diplomatically to save the nation.
Esther acted similarly. The people would have believed that they had a contact in the palace and so she specifically invited Haman to a party to imply that she was a double agent, that she had changed sides, and that she was no longer looking to save the people.
Finally, when there was not only an eis tzarah, but also nothing else to rely upon, when the people truly felt that “ein od milvado”, then they could truly pound the gates of shamayim with tefilah. It was this that led to the yeshua.
