I love your thoughts on this topic. This one statement is pretty big with Stoics. However, I've never been able the start the day off in utter negativity--no matter how true it might be! This is where the positive psychologists win--no matter how unscientific they are.
Maybe modern Stoics go the route of hermeneutics with this statement, because taken literally is too much. I just don't look at people that way.
If I could be so bold as to amend Aurelius's statement, I would add "SOME people I deal with MIGHT be meddling...". And that statement would be true. Not everyone is out to get me. If I were an emperor, maybe.
But this excerpt has always troubled me. But I get it, prepare for the worst and then when it (likely) doesn't happen you'll be relieved. A bit old-school reverse psychology most people can out-think.