systemd & the tightly couple core band vs a world of many inits

The simpler part of init scripts is not the scripts themselves but how they interact with each other. As far as the script themselves being unmaintainable spaghetti, you can do that with any language. I am sure as Upstart gains more traction more cruft and craziness will build up.

Init and bash are things that have had decades to show it's warts.

You just haven't given Upstart a chance yet. '-)