Throughout my school and university years, I was always taught to communicate in the most plain, simple, and unambiguous way possible. My teachers were good at knowing when we were filling in essays with useless fluff. My professors hated it when we used unneccessary jargon when a plain word would suffice. They told us to write as if we were trying to explain something to our grandparents.
I am a computer programmer. I have multiple degrees. I work with big data, I write compilers for computer programming languages. I read research papers and technical documents daily. After censoring my own papers after years in the classroom, it stands out like an elephant when I read or hear something that is plain fluff, unnecessarily verbose, or ambigious. I think the people using these techniques are trying to sound smart, but their credibility is instantly killed as soon as it is detected.
I am sure you have heard of 'corporate speak'. It is when your boss tells you that to assertively provide access to diverse systems, your team needs to efficiently streamline turnkey best practices to conveniently converge data from timely internal and external sources. It means nothing. It is pure fluff.
Being unneccesarily verbose is another. There is no such thing as proof by verbosity. Saying the same thing over and over again without answering the question, inserting technical jargon, or answering questions in the longest way possible (by inserting fluff) does not make it true. (This excludes people that are actually trying to say something. You can pick up the difference between someone trying their best to tell you something in a way you would understand and someone trying to confuse you with jargon.)
The last technique I hate is the use of soft ambigious language. Say what you have to say in a way that cannot be misinterpreted or create false hope. I hate it when politicians say "this billion dollar project can attract and create jobs and businesses." The keyword here is 'can'. Eating out at a restaurant 'can' give you food poisoning. But the chance of this happening is very small. 'Can' means something is possible, but it does not necessarily mean that it is likely to happen. 'Can' is a good word to use when you are throwing out possibilities that can happen, but I would not use it as justification for gambling billions of dollars.
I encounter this kind of soft ambigious language at work. "I haven't had time to work on it yet, so the changes may not be in there." Even though we know the changes 'will not' be in there, they soften is as 'may not' (i.e. somehow overnight some magical pixies came in and did their work for them) - and when 'may not' gets communicated to the client - they interpret it as '50% chance it is' and waste time testing out changes that haven't been made.
The point I am trying to say is - if you have something to say, say it in the simpliest, straight forward manner.