The concept of electrons orbiting the nucleus in circular paths was initially proposed by Niels Bohr in his Bohr model of the atom in 1913. This model was a significant step forward in understanding atomic structure, but it was later superseded by more accurate quantum mechanical models.

Here's why Bohr's model is considered a simplified view:

* Quantum Mechanics: The modern understanding of atomic structure is based on quantum mechanics, which describes electrons as existing in probability clouds or orbitals, not as definite circular paths.

* Electron Wave-Particle Duality: Electrons exhibit wave-like properties, and their behavior within the atom cannot be precisely determined.

While Bohr's model wasn't entirely accurate, it was a crucial stepping stone in the development of our understanding of atomic structure.