You get the same problem the other way. If you divide every little thing, you end up with a chain with a bunch of weak links that aren't very obvious maintained by people who may not be there anymore and you may not be in a position to go it alone.
No you don't - because you can inspect each and every link in the chain with ease. It takes very little skill to add instrumentation to a SysV script that will tell you *exactly* what it's trying to do. The same cannot be said for systemd; you can only turn on debugging and hope that it tells you what you want.
But at least you know who to complain to when things go wrong.
Many of us have tried complaining to Poettering over the years when things go wrong. He's not renowned for taking any notice.
#! /bin/bash to
#! /bin/bash -x in line 1 is often a good start, an really not that difficult to do...