Early Christianity had a problem. When life was hard but afterlife supposedly awesome, why do the hard part and not just skip ahead? Oh, but then who will toil in misery and pay tithes and be serving the kings army? Ey, presto! Tell everybody that suicide is a mortal sin with eternal suffering and all that jazz! (That in turn sprouted workarounds like killing somebody else and be forgiven for your sins before execution.)

The moralism lives on that life is holy and you leave others to struggle in their misery while you take the easy way out. And this is why it is taken to absurd lengths that people are kept on life support that only serves to prolong their terminal suffering against their own will.