Earlier quoted context omitted.
> As for a lack of system tray icons, the practical upshot is that my system bar isn't littered with multiple special snowflake applications, each with their own unique icon art style and mismatching proportions. Plasma Desktop's System Tray widget that lets you hide icons you don't want to see. You can disable the widget, or configure it to show no icons at all.
The problem with that is, that applications will assume it is present and enabled. If it is not, they will inflict a pain on the user until it is enabled again. For example Skype. With default being off, it is applications that have to be careful. They can use it, when they detect it is present, but cannot assume it anymore.
System trays exist on most platforms, and apps, especially cross-platform apps, will sometimes assume that they exist. I prefer to use a system that can handle those apps.