All Bash scripts are duck-taped by definition. It's a shitty duck-tape language.

> thousands of servers running just fine

Err yeah well you might have noticed these things called "laptops" and "desktops". SysVinit was... fine.. on servers. It worked badly on desktops and not really at all on laptops. I'm pretty sure the post introducing SystemD explained it all in detail if you want to learn something.