Maharal in his commentary Ohr Chadash:
And all the servants of the king etc. … But Mordechai would not bow; It was written in grammatical form denoting the future, for it was not done just this one time alone, rather many times, he did this, and therefore it is written in the future tense, for this is what the future tense implies concerning something that is continuous, similar to the verse, "Thus would Iyov do", And one should explain that he would not bow, that even though Mordechai could have gone by a different path and not met him and he would not be angry, Mordechai would go against Haman with the intent to do this, not to bow, and not to prostrate, and all in order to sanctify his Name Let he be blessed (G-d). And there are those raise the question, for what purpose did Mordechai do this, and he should not have put himself in danger and Israel to provoke the Wicked person? But this is not a difficult question, as we say in the first chapter of Brachot 7B "Those that abandon the Torah will praise the wicked and those that keep the Torah will provoke them". And all the more so a wicked person, who is Haman, that was prepared to be an obstacle and stumbling block for all of Israel… And even without this it is not difficult for Mordechai, sat at the gate of the king, this was due to Achashverosh that appointed him, and one does not remove himself from the appointment (see there).