They all sound plausible and likely. There are people obfuscating knowledge for all the reasons you mentioned. At the same time, it doesn't mean there's a conc

They all sound plausible and likely. There are people obfuscating knowledge for all the reasons you mentioned. At the same time, it doesn't mean there's a concerted effort to obfuscate mathematics. Explaining things is hard, because you have to create a clear picture of the audience in your mind. Then, you have to draw the lines between what they know and what you want to introduce. The curse of knowledge is a big obstacle here.