Mishpatim: Do Not Oppress The Widow and the Orphan

The pesukim state {Shemot 22}:

כא כָּל-אַלְמָנָה וְיָתוֹם, לֹא תְעַנּוּן.	21 Ye shall not afflict any widow, or fatherless child.
כב אִם-עַנֵּה תְעַנֶּה, אֹתוֹ--כִּי אִם-צָעֹק יִצְעַק אֵלַי, שָׁמֹעַ אֶשְׁמַע צַעֲקָתוֹ.	22 If thou afflict them in any wise--for if they cry at all unto Me, I will surely hear their cry--
כג וְחָרָה אַפִּי, וְהָרַגְתִּי אֶתְכֶם בֶּחָרֶב; וְהָיוּ נְשֵׁיכֶם אַלְמָנוֹת, וּבְנֵיכֶם יְתֹמִים. {פ}	23 My wrath shall wax hot, and I will kill you with the sword; and your wives shall be widows, and your children fatherless. {P}

Is this just imposition of morality via threats -- if you afflict, I will punish you, because you are doing wrong? I think so, to a certain extent. But I think that another part of the message is an attempt to teach empathy. And if someone cannot feel empathy for their plight, Hashem will cast their wives and children into a similar plight. Thinking about this happening to people one cares about, and how they would handle being in such a situation, might influence someone to empathize more with people who are not close relatives who are in this plight. And indeed, empathy is a theme in the immediately preceding context as well:

כ וְגֵר לֹא-תוֹנֶה, וְלֹא תִלְחָצֶנּוּ: כִּי-גֵרִים הֱיִיתֶם, בְּאֶרֶץ מִצְרָיִם.

20 And a stranger shalt thou not wrong, neither shalt thou oppress him; for ye were strangers in the land of Egypt.