For what it's worth, this is still FUBAR. I definitely see a bug here. I recently moved from Xubuntu -> Fedora XFCE -> "Plain" Fedora and this is when this all started happening. Both the Xfce respin and the "plain" setup were FC20. I've attempted to disable anything that might be eating things from /tmp and change all the configs I can find. The max lifetime of a file in /tmp if 60m. After teh 60m mark, it's gone. To be honest, the length of time that tmpwatch has been doing Bad Things (yes, I think force cleaning /tmp is Bad) is of little concern to me. The fact that there appears to be no way to make it stop, is a bug. When did this become tangled in the pile of spaghetti that is systemd?