I'd be very wary about asserting stylistic intent to da Vinci when it comes to engineering endeavors. Many of his architectural designs were thought fanciful and entirely unfeasible until someone actually built it, or built it with the right materials.

I would hazard that there is a lot of thoughtful consideration that went into the ornithopter designs, to the extent that a breakthrough or major insight lies waiting for anyone able to decipher or parallel da Vinci's reasoning.