Well, the issue here is that inflation is a rather complex phenomenon. In the simplest models, what you need is for the majority of the energy density to be in a particular kind of field. This field, due to the way it interacts, must experience a sort of potential energy depending upon its value. And it must have enough potential energy such that it drives an expansion so fast that the expansion slows down how quickly the field is able to roll down to its minimum value. Then, once it reaches that minimum, it has to evaporate into standard model particles very rapidly.
So it's not quite so simple an idea that it can merely be the result of some simple principle. At least, not so directly.