It's interesting that while many of them concern relations between human beings, the phrase "אֲנִי, יְהוָה," "I am the LORD," repeats very frequently. IMHO, this is to illustrate that we aren't to look for logical, sociological, biological, health or botanical reasons for these Mitzvot. It's forbidden to search for rationales and excuses to ignore them.
In Israel and in the Jewish world, unfortunately, there are periodic reports of Torah, Orthodox converts discovering that other Jews will not recognize or even have "cancelled" their conversions.
Sometimes Jews who converted with totally sincere intentions and under the supervision of fully Torah observant rabbis, relax their observance post-conversion, just like born Jews whose observance fluctuates throughout life. In this week's Parsha, Torah Portion, there's a sentence which could be considered defense the convert:
לג וְכִי-יָגוּר אִתְּךָ גֵּר, בְּאַרְצְכֶם--לֹא תוֹנוּ, אֹתוֹ.
33 And if a stranger sojourn with thee in your land, ye shall not do him wrong.
I like to think of it that way, but I'm troubled by the line which follows:
לד כְּאֶזְרָח מִכֶּם יִהְיֶה לָכֶם הַגֵּר הַגָּר אִתְּכֶם, וְאָהַבְתָּ לוֹ כָּמוֹךָ--כִּי-גֵרִים הֱיִיתֶם, בְּאֶרֶץ מִצְרָיִם: אֲנִי, יְהוָה אֱלֹהֵיכֶם.
34 The stranger that sojourneth with you shall be unto you as the home-born among you, and thou shalt love him as thyself; for ye were strangers in the land of Egypt: I am the LORD your God.
Ironically, when I mentally planned writing about this, I had no doubt that I would use verse 33 to 100% defend the convert. But the qualification in verse 34 makes me wonder. We, the Jewish People, didn't live in Egypt to become Egyptians, nor did the Egyptians treat us well after the initial enthusiastic welcome.
Maybe we should delve more deeply in this, as in the "contract" between Pharaoh and Joseph, like the "contract" between a convert and the Beit Din, Rabbinic Court which approves/certifies the conversion. The Egyptians broke the contract when they made us slaves.
That aspect makes sense, when you read the next two verses:
לה לֹא-תַעֲשׂוּ עָוֶל, בַּמִּשְׁפָּט, בַּמִּדָּה, בַּמִּשְׁקָל וּבַמְּשׂוּרָה.
35 Ye shall do no unrighteousness in judgment, in meteyard, in weight, or in measure.
לו מֹאזְנֵי צֶדֶק אַבְנֵי-צֶדֶק, אֵיפַת צֶדֶק וְהִין צֶדֶק--יִהְיֶה לָכֶם: אֲנִי יְהוָה אֱלֹהֵיכֶם, אֲשֶׁר-הוֹצֵאתִי אֶתְכֶם מֵאֶרֶץ מִצְרָיִם.
36 Just balances, just weights, a just ephah, and a just hin, shall ye have: I am the LORD your God, who brought you out of the land of Egypt.
Yes, that must be it. The word of the Beit Din, to consider a person Jewish is a contract, and once it's signed, it's forbidden to change the conditions.