E. coli 'notices' only a small range of events, defined by the ligands that bind to its receptor complexes. It has no directional sensitivity, and can produce only relatively minor changes in its environment - altering its location in the environment, and consuming chemoattractants. Consider, by way of contrast, the beaver. This organism has a highly developed sensory system, and through behaviours such as dam-building significantly perturbs its environment, and its own ongoing relationship with that environment. In a simple homeostatic system like a thermostat, there is little scope for variation in behaviour, even given an appropriate operational environment.
Structural variability is by definition a minimal resource in inanimate objects.
Their structure is defined largely by environmental contraints and forces - weathering in the case of geographical features, or the laws of physics, which describe constraints that apply to all physical systems. Even despite these limitations, complex interplay between system and environment can still occur, for example during the growth of snowflakes, or where collections of objects are treated as a unit of analysis, affording a great deal of structural variability with regard to the relationships, spatial or otherwise, which hold between component parts. The dynamical structure of biological systems affords great scope for variation. In many cases this potential variability is restrained by the action of homeostatic processes, which in turn engenders a capacity and a disposition to respond to perturbatory forces. From the perspective taken here, the nervous system is significant as a highly flexible intermediary between sensory and effector surfaces.