Slade, I apologise for the very long response. I seem to write much when I think it's important, I am very interested or passionate. Plus, I like to write.
I forgot to respond to a few of your comments above. I don't know if it is positivity bias or inundation by the propaganda and so pervasive that people use it and see it, but don't notice it (sexist language, racist language and similarly related topics). I don't think most people notice it. I wear brand clothing, but everyone does. But most don't notice it. They just wear it. I did a tiny informal poll at the airport where I worked once and asked a few people what was on the front of their T-shirt. None of them knew. None. The thing is, I am not special by any means, but I was introduced to this subject many years ago and began studying it informally. So I made myself used to seeing it everywhere. I got deeper and deeper until recently, with the study of feminist psychology, and realized it just wasn't "regular" propaganda, and I started studying and researching and writing about the language aspect embedded into all the rest.
To answer your questions, I don't think it's so much of a positivity bias but rather a complete smothering of media, language, and other forms of propaganda so that people are buried by it and they don't notice it. I have a constant battle with men (mostly) and many women that calling a grown woman a "girl" is infantilizing ( a word I have difficulty rolling off of my tongue most of the time) and insulting. Most don't get it. "That's just the language," or, "That's the way we talk in English."
I don't think it is one academic field, though. Edward Bernays (there are a few books by him that discuss propaganda in depth, since he was the foremost practitioner of it in the 20th Century) borrowed from sociology, from psychology (via his uncle, Sigmund Freud), and everywhere he needed to to get a point across (but those are the only two I know of). Cognitive psychology comes into play, too, and those principles were first discovered by BF Skinner, I think. ). But advertising and marketing and publicity and public relations and not distant cousins of any of the above. They are "children". I say "children", because after propaganda was used in WWI in the US, it became a dirty word, and so, Bernays had to find another term. He found public relations. The rest are the same, just offshoots. Most people will deny that they are the same thing, which may be why it is sometimes difficult to discuss propaganda with most.
You also touch on some very important points that I am very interested and passionate about. How to teach people about this? I have pondered this often. I don't think there is a site that people can go to to so that they can understand it that will explain all of this. People have to find and look for the information. It can be found in several places. I know there is an archive at Leed's University for Phil Taylor's links, and there are many. BUT, I think this is a very good subject to teach. I want to teach it in small communities and small community groups, and when I say teach, I want to teach people to recognize it and possibly keep it out of their community (however limited that is). I would like to teach this via participatory action research. Is this something that may be of interest? The catch/trick would be to get funding from somewhere or take donations in community or elsewhere, but essentially the community members involved would be co-researchers for each project. I do think it is possible to do this.
A radio show may also be a good idea, too (I am going to revive my Internet radio web site soon, and that may be an option, but that is another conversation.).
Having said all that, I know there is much more I can and need to learn.
Again, apologies for such a long response.