To be fair, tons of scientists and technical people believed at that time that telepathy might be real. For example if you go back and read science fiction from the 40s, 50s, even 60s, there is a ton of telepathy and mental powers. This reflects both the authors’ efforts to predict future scientific advancement, and their audience’s willingness to believe it.
No it represents the editor's (John W. Campbell) passions - he would suggest using those ideas to authours and was more likely to accept stories with those ideas.
He had an overwhelming presence in SF until the New Wave of the 1960s
It’s more accurate to say that Campbell became a huge presence in science fiction by publishing the stories he did. Their popular success reflected a desire in the culture to read what was being published. Larry Niven is one example of an author who did not go through Campbell but yet had many mental powers in his stories and found huge success.
Many universities had depts to study “parapsychology.” The end of that era is the basis for the opening of Ghostbusters. I’m using popular media as shorthand for how wide-spread these ideas were, but military and intelligence operations seriously studied this stuff too, and in many countries, not just the U.S.
This is the way science goes; people can only work with what is known at the time. Newton was doing alchemy while inventing the basis for modern physics. It’s tempting to look back and condemn people by the standards of what we know today, which is based on additional evidence and theory developed over decades or centuries since. But I think it inhibits understanding of how such knowledge is created over time.
