I agree with you largely. It isn’t always a dark pattern. It is a dark pattern if it’s used shadily or maliciously, for example to trick you into downloading adware in an installer. It’s not a dark pattern, but rather good UX design if it’s used in a context to indicate a likely default choice, for instance:
We’ve detected your system is set to Dutch. Is Dutch your preferred language?
[No, let me change] [Looks good]
Maybe someone else has other examples of good uses. It’s not appropriate everywhere.
Emphasised “continue” or “default” buttons have been around for a long time. In a software installer, nonstandard options are often less emphasised than the standard ones. For instance when choosing an installation location it makes sense for the default option, which is fine for most users, to be emphasized. If the continue and change location buttons were equally prominent the user might believe that a choice must be made here or that you are expected to choose a location. The experience of installing is more streamlined, less confusing for the less technically proficient, and requires less cognitive load when emphasis is used well.
As I said in an earlier comment, something being a dark pattern is entirely a matter of context. If used to encourage the user to shell out for gems in a mobile game, it’s a dark pattern. If used to make user experience better, it’s just good UX.