Here's why:

* Structure and Support: Cell walls are rigid structures that provide support and protection to plant, fungal, and bacterial cells. They are primarily made of cellulose, chitin, or peptidoglycan.

* Lack of Motility: Cell walls are static structures that do not possess the ability to contract or expand for movement.

* Internal Mechanisms: Cellular movement in organisms with cell walls is primarily driven by internal structures like flagella, cilia, or cytoplasmic streaming (in plants).

In summary: Cell walls are for structure and support, not for movement.