Linux

So, first of all, I barely ever had to work with d-bus directly - I used it a few times and it was fine to use.

Without any well-defined standards, a protocol is essentially useless and/or lawless

When I look for "D-Bus Specification", I get this: https://dbus.freedesktop.org/doc/dbus-specification.html. This LOOKS like a proper documentation of the standard to me.

the general lax nature of how endpoints are intended to be defined ... is a significant factor for why many applications are the way they are

I feel like this is the same complaint people have about other things, like PHP for example. They see shitty PHP code (like wordpress) and are like: "Oh my god PHP is such a shitty language because this application is written like shit". But I don't blame a language, a framework or a protocol for the failures of the users. I don't feel like an application that close to the system core has to be absolutely "dummy proof". At some point, we should just expect that people know what they're doing, and if they don't, we should blame them, not the underlying technology.