to say: Since a sin offering is brought for atonement, people do not distance themselves from it after it dies, as they realize that it is no longer fit to atone. Therefore, in order to ensure that people do not show disrespect, the rabbis decreed that one is liable for its misuse. But with regard to other sacrificial animals of the most sacred order, since they are not brought for atonement, people still distance themselves from them after the animals die, and therefore one might think that there is no need to decree that they are subject to the halakhot of misuse. Consequently, Ulla teaches us that even other sacrificial animals that die are subject to misuse by rabbinic decree.
וחטאת שמתה מי אית בה מעילה? והתנן: חטאות המתות ומעות ההולכות לים המלח – לא נהנין ולא מועלין!
The Talmud asks: And is a sin offering that died subject to the halakhot of misuse? But didn’t we learn in a baraita: With regard to sin offerings that are left to die because they are no longer fit for the altar, from which one is prohibited to derive benefit, and likewise money from which one is prohibited to derive benefit, which goes to the Dead Sea to be destroyed, one may not derive benefit from them ab initio, but if one derived benefit from them, he is not liable for their misuse?
They say in response to this question: With regard to sin offerings that are left to die, since even during their lifetimes people distance themselves from them, as they are no longer fit for sacrifice, there was no need for the rabbis to institute a prohibition of misuse. This is to the exclusion of a sin offering that was fit during its lifetime, as people do not distance themselves from it, and therefore the rabbis saw fit to institute a prohibition of misuse after it dies.