You just need to watch and pay attention to all the little details. Everything makes sense. At the core of this series, there is an emotional truth to the characters, and all of the pieces fit. Every single character is motivated by two forces -- either fear of, and/or desire for something, with the degree and mixture of those two polar elements determining who they are, and what choices they make.
Just look at the Origins (Stoneheart) episodes. It's all about Marinette choosing what she's going to be motivated by --. her FEAR of the responsibility, of not being able to live up to her idea of the perfection of being a superhero, a "chosen one"... or her DESIRE to do what she knows is right, and to help people (especially in the form of her new friend Aliyah). Ultimately she chooses her desire to help, to do what's right, over her fear, and becomes a true hero.
I think the fact that neither Hawkmoth nor Gabriel Agreste ever deals with people personally and directly, but always erects fortresses, walls and protective barriers between himself and others (physically and emotionally) shows that he succumbed to his FEAR long ago. He can't withstand his fear emotionally, so he will do it the only way he knows. He DESIRES taking control of everything and everyone around him -- he's a control freak. Tell me I'm just making this up, that it's not really there in his every response to things in the episodes.
Of the millions of people who inhabit the city of Paris, what are the odds that nearly ALL of them who've been akumatized are already personally known to either Marinette or (occasionally) Adrien before Hawkmoth chooses them as his pawns? It's quite a stretch of statistical logic to think that the people Hawkmoth has chosen so far are the only people in Paris feeling anger and hate, and even worse logic when you consider that all that Hawkmoth needs to do to succeed is to pick a victim to akumatize with whom neither Marinette or Adrien are familiar in any way -- a complete and total stranger to them. If they don't have a clue who the akumatized villain was before being transformed and what was the source of their anger, they haven't got a chance of discovering what his akuma is and defeating him, so this is exactly what Hawkmoth should be seeking to do.
Yet it's exactly the opposite of what he actually IS doing... akumatizing mostly people with whom Marinette is intimately familiar -- her classmates. Even in the few cases where his victim isn't someone she's known very long... like Mr. Pigeon, he isn't transformed by akuma until AFTER Marinette notices the man's trouble in the park with Officer Roger, and feels sorry for him. ALL of these people have some emotional significance, even if it's small, to Marinette (or in the case of Copycat, the reverse). That must be necessary somehow for Hawkmoth, or he wouldn't be following that pattern, which strongly indicates to me that he KNOWS who Marinette really is -- and possibly Cat Noir as well, but that's somewhat less clear.