Question

In the Mishnah in tractate Chagigah, chapter 1, mishnayot 6–7, it says:
(6) One who did not bring the festival offering on the first holiday of the festival may bring it throughout the entire festival, and on the last holiday of the festival. Once the festival has passed and he did not bring it, he is no longer obligated with respect to it. About this it is said: “What is twisted cannot be made straight, and what is lacking cannot be counted.”
(7) Rabbi Shimon ben Menasya says: What is a distortion that cannot be corrected? One who had relations with a forbidden woman and fathered a mamzer through her. If you would say it refers to one who steals or robs—he is able to return it and thereby correct it. Rabbi Shimon bar Yochai says: “Twisted” is applied only to one who was initially proper and then became distorted. And who is that? A Torah scholar who separates himself from the Torah.
I’m asking about the side discussion of “what is twisted cannot be made straight.” What place does it have here? Obviously there are many things in the world that cannot be corrected, outside Jewish law as well, like ruining a dish or killing someone, and in Jewish law too, like desecrating the Sabbath, or not waving the lulav, or not building a parapet until the house collapsed. So what is special about missing the make-up time for the festival offering? And what do the additional opinions—dealing with the plain meaning of a random verse in Ecclesiastes—have to do with this? Do they affect anything in the tanna’s statement? Are all three opinions in this Mishnah here about “what is twisted cannot be made straight” (the festival offering, a mamzer, and a Torah scholar who left Torah) really just a discussion on the level of the plain meaning of the verse?