Why did Detective Di Renjie hack Yuan Tiangang?

Sorry, I haven't read Detective Di Renjie, but I can try to give a possible explanation based on my interpretation of general literary works:

In some literary works, Yuan Tiangang is portrayed as a mysterious and evil villain. This may be because Yuan Tiangang's historical image is special, and because he is proficient in divination, geomantic omen and other mysterious things, it is easy to be portrayed as a mysterious and dark villain. In Detective Di Renjie, if Yuan Tiangang is portrayed as a blackened image, it may be because he used his career to win the favor of Wu Zetian, so he intervened in politics, plotted evil deeds, and even created a huge organization similar to snake spirits. This setting can increase the suspense and conflict of the story and make the plot more interesting.

But this is only a possible explanation, and the specific reasons need to be deeply analyzed according to the content of the work and the author's intention.