Systemd as tragedy

He basically says that writting a system is the fast thing.

Verifying that it is correct and documenting it is 75 % of the work, that is if you want
something which is a software PRODUCT, not something which will bite
the customer (and your own customer engineer) hard. Which means that the
guy on your side that sold the system will get a very angry phone call (i
say so because IBM was never afraid to send a stiff bill, but the IBM representative
would theese days by his boss be expected to leave a note with her mobile phone number, saying any trouble call, anytime.)

Yeah i know that in many cases supplied shell scripts for example hadnt been thru that ie the check .. is this correct ? Does it do what it needs to ? Can we document it ? Describe it ?