For three reasons:
First of all, self-perfection depends on choice and effort. And obeying the laws of morality requires choice, as is well known.
So the laws of morality contain enough potential to fill that role.
Second, there is a reality deficient in terms of evil, and the laws of morality can repair and perfect that reality.
That is, up to this point the laws of morality and the commandments between one person and another can indeed serve the role of self-perfection.
Now I’ll give a reason why it is preferable to choose דווקא that:
Third, if we already have a suitable framework, we have no reason to try to add more roles to it—by Occam’s razor.

I didn’t understand any of the reasons.
1. Self-perfection through non-moral laws also depends on choice.
2. And perhaps there is also a deficiency on a non-moral plane, and that is what is completed through the non-moral commandments.
3. Occam’s razor is a principle for choosing between two possibilities when there is no information. But I’ve never heard an objection based on Occam’s razor against existing information—asking why it isn’t simpler. Do you also ask why there are four fundamental forces in physics and not just one, on the basis of Occam’s razor?

2. But the whole deficiency is in us! And in us there is no deficiency on the non-moral plane. Because if God did not command it, there would be no deficiency on that plane.

As for the rest, yes, it’s a bit weak, but it expresses my objection—why the Torah so strongly contradicts the laws of morality and basic reason.

It is not necessarily true that the deficiency is only in us. Perhaps it is also in the world. Beyond that, God’s command does not necessarily create the religious deficiency, just as it does not create the moral deficiency (though the Euthyphro dilemma is relevant here, and this is not the place to go into it).
The Torah also does not contradict morality and reason, except in a few cases. In most cases where there is a mismatch, it is an a-moral commandment, not an anti-moral one.
As a rule, we do not hear objections of the form “one can force the question.” We only hear “one can force an answer,” and even that is forced.

What is the difference between a-moral and anti-moral?
For example, the destruction of Amalek, the status of women, sacrifices, and the like—is that moral?!

A-moral means something unrelated to morality. Anti-moral means something that contradicts morality. Most commandments you can think of are a-moral (all the dietary prohibitions, Sabbath, most of the commandments dependent on the Land, and many others). As for the destruction of Amalek, its status is not at all clear to me. On the status of women, there are different aspects. Sacrifices—the main obligations of offering them are anti-moral, but there are also many other neutral details.

So does it not bother the Rabbi to observe so many anti-moral and foolish details? For example ritual hand-washing, Grace after Meals in particular, or prayer in general (which, according to the Rabbi, does not help).
Or the obligation of sacrifices?

Nati, if you’re not going to read what I write, then we’re both wasting our time.