I think what is sometimes lost in translation, due to both parties frustration in such discussions, is that many people who have their own way of doing things fail to realize their own way is based on a handful of books or online resources. These resources in turn stem from further resources, which can all generally be traced back to a range of spiritual traditions.
This generally means that those eclectic practitioners who practice their craft, while not necessarily wrong, are also only partially informed. In this partial view, they may miss things that others who have a deeper understanding of a particular form of magic might see. They might also have different ways of explaining/describing things that don't exactly align with more traditional terms/methods.
The result is the proverbial teenager screaming that they know what's right to someone who, through deeper experience/education may know better.
Not always, but often.
It also tends to mean that somebody, from either side, views only part of the situation and thinks they are correct. They then refuse to learn more of either side, adapt with the situation, and grow from the experience.
The traditional, rational methods are not always correct. There are certainly things in this world that we are not able to explain. However, it is also necessary to examine things rationally, or else you are giving in to ignorance and simply believing everything without intelligence. And this, largely, is the source of the frustration, anger, and "fluffy" label.
Frankly, expressing yourself in a manner that seems very much like a youthful tantrum, where one might shout "I don't have to prove myself to you or anyone!" before storming off to one's bedroom and slamming a door tends to lend some credence to this stubborn lack of desire to understand, learn, and grow within a situation.