I don’t quite believe that there was no moralistic sentiment directed against it when high frequency started, or even before that when whatever changed changed. The fact that people weren’t currently writing about the status quo, but then write about a change to it isn’t surprising.
The NYT had a pretty well received article on it back in 2009. Michael Lewis published a book criticizing HFT back in early 2014 which is a pretty good sign there was indeeed moralistic sentiment against it.
