Businesses do not want to spend millions of dollars on a system that does not perform the way that they were expecting.
The thermal variables shown in the chart are not power conjugates and thus do not meet this criterion.
Similarities also exist; the two systems can often be analysed by the methods of Euler, Lagrange and Hamilton, so that in both cases the energy is quadratic in the relevant degree(s) of freedom, provided they are linear.
Furthermore, these sorts of systems follow the capacitor or spring analogy, in the sense that the dominant degree of freedom in the energy is the generalized position.
In more physical language, these systems are predominantly characterised by their potential energy.
On the other hand, flow systems may be easier described by the hydraulic analogy or the diffusion equation.
Field theories, in particular electromagnetism, draw heavily from the hydraulic analogy.