Why all processes except process 0 are allowed to die?

[dhinf]

All processes except 0 are allowed to die. But, if the process with id 0 dies all other processes will be killed.
It's a strange behaviour in terms of fault tolerance.

used branch: next

Example:
state_vec_2.cpp.txt

output 8 processes:
/bin/sh: line 1: 8544 Killed ...
/bin/sh: line 1: 8550 Killed ...
/bin/sh: line 1: 8549 Killed ...
/bin/sh: line 1: 8548 Killed ...
/bin/sh: line 1: 8545 Killed ...
/bin/sh: line 1: 8547 Killed ...
/bin/sh: line 1: 8546 Killed ...