question: why `exit(0)`when parent pid is 1?

[PoiScript]

Hello, I was trying to run my SketchyBarHelper as a launch agent. But i'm encountering a problem that the helper exits if its parent pid equal to 1 (which is launchd). I found out this behavior was introduced by this commit https://github.com/FelixKratz/SketchyBarHelper/commit/73ee34d377f62fc12ddbf519a2bcdb4b7946292a for handling kill signals, but I don't have any detail or context about this change. It's there any workaround to run the helper by launchd?