Assuming you selectively quoted me in good faith before asking "who is harmed", you should read the whole SEP entry on the ethics of manipulation, and then you should review the works it references.
- Whoever hires the author for their software engineering or data science expertise in part because of this blog post will pay for substandard work.
- By deceiving their audience as to the accuracy and precision of the demonstrated techniques, the author undermines the audience's ability to make good decisions about when to use or how to reason from the results of machine learning algorithms.
- The author disrespects their audience when they misrepresent themself, their work, and their results.
https://plato.stanford.edu/entries/ethics-manipulation/
But to answer you directly:
- Whoever hires the author for their software engineering or data science expertise in part because of this blog post will pay for substandard work.
- By deceiving their audience as to the accuracy and precision of the demonstrated techniques, the author undermines the audience's ability to make good decisions about when to use or how to reason from the results of machine learning algorithms.
- The author disrespects their audience when they misrepresent themself, their work, and their results.