Unfortunately linux often STILL doesn't handle plugging and unplugging devices very well and it kind of seems like this has gotten worse not better with systemd.
Also you seem to be conflating dealing with devices with initialization of the system. Dealing with such devices has insofar as I'm aware always been handled by c code in and out of the kernel whereas at one time initialization of services and orchestration of components was handled by a scripting language.
This is to say that a bash script may have brought up different components and services but that c code that makes up the component is in charge of actually managing said device.
Its obviously feasible for both c (or any other language) code and orchestration of start up and shut down of services to be buggy but its not equally easy for end users to fix their own problems in all cases.
Ideally bugs get reported to those who are most capable and the underlying code is corrected however if said labor isn't paid to work on their project hours to do so may be in short supply and it may frequently fall on users to lend a hand.
This is a numbers game. If you have 10000 users and 10 of them are qualified to solve such problems you may be lucky to get the help of 1 to submit patches or post a solution to a problem on a forums for others to use before the upstream problem is fixed.
If 100 are qualified you are 10x as likely to find help to solve a problem. I have on many occasions come across a solution months or years before an official upstream solution came into being. You are suggesting that most sysadmins might find it challenging to solve their own problems. They don't always have to. Merely having comprehensible user friendly systems make it more likely that one of their fellows can help them do so and more likely that such solutions travel both laterally between users and hopefully upstream solving the problem for all.