Monetary theory has some very well defined concepts. But those only appear on the equations, and when people go naming them they go and mix with the same names they use on unrelated discussions.
And then we get some completely ridiculous things like people arguing that the Keynes return of investments apply to each investment inside an economy.
I don't think this is exactly it. One can try -- and try fruitfully, for these theories have been useful in practice -- to match 'money' and 'inflation' and 'debt', in their macro senses, to everyday experience, with the caveat that they're aggregate concepts that affect individuals and various productive activities differently, and that they (money especially) can behave a little weird.
What happens instead is that people have feelings about what these concepts are supposed to mean, and then use that to make a political statement. The reason armchair- and pseudo-economists are so eager to say things like "Money is really about X" or "Money is really about the opposite of X" is they want to hijack the word 'money' and the meaning it has in the brain and turn that into politics.
These confident takes are more directly engaging, whereas economic pronouncements are wonky and weird in a way that's more relatively neutral or at least not obviously political, so the gravitation is towards the bad and confusing takes.
And then we get some completely ridiculous things like people arguing that the Keynes return of investments apply to each investment inside an economy.