http://news.janegoodall.org/wp-content/uploads/2016/11/perce...
So the mystery is not why it went down, it was why it was higher initially.
Of course, most CS graduates don't do science, but actual engineering work. That doesn't make CS any less of a science though, it just means that most people employed in private companies don't do it.
"Academic areas that are associated with the term liberal arts include:
Arts (fine arts, music, performing arts, literature)
Mathematics
Natural science (biology, chemistry, physics, astronomy, earth science)
Philosophy
Religious studies
Social science (anthropology, economics, geography, political science, psychology, sociology, Linguistics, history)"
Note the absence of engineering disciplines.
https://en.wikipedia.org/wiki/Liberal_arts_education
Vs. engineering or engineering sciences.
See for example how Stanford groups things (CS is part of the "School of Engineering").
https://registrar.stanford.edu/everyone/enrollment-statistic...
And then note the difference in enrollment in "chemistry" (the science) and "chemical engineering"
https://www.acs.org/content/dam/acsorg/membership/acs/welcom...
However, in Germany we also have "Naturwissenschaften" and "Ingenieurwissenschaften".
https://de.wikipedia.org/wiki/Ingenieurwissenschaften
https://de.wikipedia.org/wiki/Naturwissenschaft
So it's a common distinction: figuring out how nature works vs building stuff.