I don’t understand this logic. How is it in interest of the propaganda machine to make it appear that common people are against Putin? Surely they want to portray that majority like him and support his actions (which is also why they manipulate these stats you linked).
Also, Putin and his elite don’t actually give a damn about sanctions affecting “common people” (see eg post-Crimea sanctions), so I don’t see why they’d worry so much about it as to fabricate every single post on Reddit.
Navalny does have a lot of enemies: if you look at this page https://fbk.info/investigations/ (use Google translate), you will see mentions of dozens of people. He keeps investigating into them in great detail and exposing their illegal wealth. They aren't that nameless, they are rich and powerful people, some of them are sure to have friends within GRU.
Not saying that Putin didn't order it, just pointing out that the group of people with motive and means to do it is bigger than just him.
It seems that this stereotype is too generic and sweeping to be useful even if it was true.
Instead we could use facts that are already known about e.g. Putin -- that he's an individual for whom sowing fear is more important than not being blamed, as the other similar poisonings have shown.
Accurately predict the future, huh? Are you a fortune teller?
What you’re describing is nothing more than a hurtful bias, and please call it as such.