You have discovered a basic principle of theory: Make your theory only as complicated as it is necesssary to explain the phenomena you want to explain. It is also known as Occam's Razor.
It results in models. Models are analogous, simplifying: They basically say that things would work like something else in some aspects (the simpifying part), but in another sense different. That is why a model must contain the actual explanation by analogon as well as a commentary for the differences. See the last chapters of Empiricism and the Philosophy of Mind by Wilfried Sellars, where he uses this picture.
Coming to the problem of electrons: The circular-path model, as you call it, has been used to explain two phenomena: 1) Atoms are not solid 2) They have a massive, positive core and small, negative charges around it with a really big deal of nothing between. That is the problem Ernest Rutherford has been confronted with. What is more obvious than using a model that looks like the sun and its planets?
For understanding some phenomena, this model is enough. And it has one striking feature: It is easy. Why using a more complicated model for explaining phenomena that become perfectly understandable using this one?
Now, if you want to explain more phenomena (historically, this happened some time after 1911), you have to develop a more complicated model, which explains all of them. But the more complicated, the more abstract and harder to understand it will become.
I think your teacher is rightfully only using this easy model. Because explaining it in the more modern models would involve higher mathematics and a really high level of abstraction and knowledge. The most advanced models involve equations that aren't fully understood by more than a handful people worldwide.
And now the point behind all this: Even this complicated, scientific, sophisticated model is still...just a model. It basically says "Insofar as we can measure (up to now), what we call atoms behaves like the variables in this equation". It is how we are able to make sense out of what we see. It is not what it actually and finally is like. This would not even be a scientific theory, see Popper's falsifiability.