Uniqueness

If they sleep in a hostel when there are several people in the room, seemingly this is not only a minimization of the prohibition, but there is really no prohibition at all, right?

The prohibition is not a singularity but rather entering a state of forbidden contemplation. When you sleep with a woman in the same room, it is not sleeping in a room. Although I did not notice the possibility of sleeping with other people in the same room. If it is about sleeping with other people in the same room - I really don't think there is a problem with that.

The Shulchan Ar-Rahman wrote in section 14 that it is permissible to desecrate Shabbat in order to save a Jewish daughter from conversion and destruction. And the Mishnah clearly states: “When a person completely converts, he will desecrate Shabbat and practice idolatry all his days, and if he desecrates Shabbat once, it is called a minor sin against this.” So, we recite the halakha that states that a minor sin is committed only to prevent a major sin from being converted. What does the Rabbi say? That a minor sin is committed only to prevent a woman from converting? Or is it possible to divide a language into those who desecrate it and not those who desecrate it. And in that case, it is considered “without any pleasure for the creation” since he has no control over it. What does our Rabbi say?

The Torah and the Rashba disagreed on this, and Rav Yisrael has already written about it extensively in Tecumin (Issue 1 or 2).
I do not think that the intention is for a great and perverse prohibition, which the commentators have extended regarding baking bread in the oven on Shabbat. Here it is a kind of fiqun (spiritual).
There is no difference in halakhic law between desecrating someone and having him desecrate. And carefully examine the early disputes regarding feeding a sick person with carrion or slaughtered meat on Shabbat, none of which (except for the HaShem of the Tashbaetz, which rejects it) raised the issue that by slaughtering I desecrate Shabbat for him, and by slaughtering meat I violate the prohibition for myself. Ha, kamen dala shena. We also find in the responses of Ajam and Ahiezer that they rejected the Mishnah of the Sages regarding performing a dangerous surgery in a place where there is doubt about the danger, which the Mishnah of the Sages said should be given to a Gentile doctor, and they rejected his words because he did not hate others.