Harry does this over and over. He's protecting Murphy. He's protecting Kim. He's protecting Molly. Can you see an ongoing pattern in what Harry is doing.
Most of it are unintentional. The harm is done out of ignorance rather than out of malice, but it is harm done by Harry regardless.
1. He practice as a real wizard openly and advertise himself in the yellow pages. This opens the pandora box. It provides a convenient avenue whereby vanilla mortals and unprepared practicianers the chance to access the more dangerous and deadly part of the supernatural world. Though we may argue that people like Susan can and probably will get into the dark and deep end of the supernatural world by themselves, Harry openly practicing as a real wizard makes matter a lot worse. Harry done this despite the disapproval of the senior members of the council and he know it.
FM:
"Oh, come on, Harry," she told me. "You'reChicago 's only practicing professional wizard, and you're the only one who can help me." She leaned across the table toward me, her eyes intent. "I can't find the references for all of these symbols. No one in local circles recognizes them either. You're the only real wizard I've ever even heard of, much less know. I just want to know what these others are."
As we can see, Kim Delaney, a somewhat connected practicianer cannot easily find access to a wizard. Without Harry, gaining access is not so easy, especially during the early parts of the series where the world is still peaceful and stabil and secrecy is held tight.
2. Harry gave partial information to amateurs. Though he warm them about the dangers afterwards, his conduct are likely to encourages the amateurs instead. For example: Harry explain the 3 layered circle to Kim, but he only explain the first and second circle and he lied to Kim about the 3rd circle. Harry told kim that the 3rd circle is gobbledygook. He show kim some of the stuff, hide the most interesting ones and then told her "Don't do this!"
We know how that kind of admonission tends to encourages the curious to do the exact opposite. This is most prominently shown when it comes to Molly. The reason why Molly dabbles with magic and end up doing black magic is because the impression Harry made. I am certain Charity done all she could to warn Molly about the dangers of magic, but we know how that turns out. To a certain extent this happened to Susan too.
3. Harry involve amateurs in high level game. This equivalent to involving civilians in military matters. It is tabu. In Harry's defense, he is kind of desperate and outmatch, but it is still wrong. It is the bad out of the worse but it is still bad.
This is what Morgan say about it:
He shook his head wearily. “There’s a reason we don’t encourage amateurs to try to act like Wardens,Dresden .”
I scowled at him, got a bowl of warm water and some antibacterial soap, and started cleaning up his left arm. “Yeah, well. I didn’t see any Wardens doing anything about it.”
“Chicago is your area of responsibility, Warden Dresden.”
“And there I was,” I said. “And if they hadn’t been there to help, I’d be dead right now.”
“Then you call for backup. You don’t behave like a bloody superhero and throw lambs to the wolves to help you do it. Those are the people you’re supposed to be protecting.”
“Good thinking,” I said, getting out the bag of saline, and suspending it from the hook I’d set in the wall over the bed. I made sure the tube was primed. Air bubbles, bad. “That’s exactly what we need: more Wardens inChicago .”
Harry is a wizard and in the later parts of the series, a warden of the council. He is not suppose to involve the alpha's at all. If he intended to involve the alpha's he need to provide information, trainning and equipment, the way the council train and equip wardens. He is ill prepared and for a wizard that is a fatal mistake.
In the later parts of the series, especially after book 12, most people involve with Harry already well informed and quite expirienced. Most of them already survive and sometimes even triumph against supernatural powers at least once. The problem of involving amateurs in the game of heavy weights becomes less prominent as a result.