Another form of this that seems to have taken over online discussions in the last few years is “<person> did <thing> because they are evil” (or rich).

As an example, I’ve noticed that privacy-related discussion on HN is often thought-terminated by comments that reduce down to “<company> is doing <perceived privacy-destroying thing> because they want to destroy your privacy”. On reddit, a common form of this is “<politician> is doing <something implausibly comic book villain-y> because they are evil”.

When the motive isn’t clear, I often enter these discussions trying to learn more about why - but more often than not, I just leave feeling the same way as the author here.