The first I recall seeing the STEAM acronym was John Maeda's efforts to popularize it in the early 2010s e.g. https://scholarship.claremont.edu/steam/vol1/iss1/

The first I recall seeing the STEAM acronym was John Maeda's efforts to popularize it in the early 2010s e.g. https://scholarship.claremont.edu/steam/vol1/iss1/34/ https://scholarship.claremont.edu/steam/vol1/iss1/34/ His focus at the MIT Media Lab was teaching artists and designers to program, and my understanding is that he continued that as the president of RISD, so it definitely was not intended as an acronym to convince art/design folks they didn't need to learn STEM. I also never personally interpreted the attempted inclusion of Art as implying a lack of creativity in the other domains any more than the inclusion of Math implied a lack of mathematical aptitude in the other domains.