To me, the most poisonous example that contrasts the traditional design with Freedesktop's design is acpid contrasting logind. In the former case, an acpi event is sent, and acpid simply executes a file such as `/etc/acpi/action/lid_down.sh`. That file can contain anything the system administrator wills, from a simple script that does nothing more than `systemctl sleep` to whatever complex task he could desire.
The last time I checked the situation, logind had replaced this powerful, and simple mechanism with a configuration that offers nine options to execute when the lid is pressed, none of which involve executing a simple file. Of course I can edit the source code and recompile to allow it to do what I want it to, but I would far rather simply quickly alter a simple shell script to do so.
And luckily I can, because I do not use logind but acpid, but that does not change the ire I experience when dealing with many Redhat and Freedesktop people who make it very clear that I should be using logind, that it's better, and that they create artificial dependencies on it to as Poettering calls it “gently puh” me in that direction.