There is a clear drive for efficiency in thermodynamic dispersion behind every movement, every action and every thought - at the particle and yes, at the sub particle level as well, what sets the direction for movement is the path to the longest possible cohesion of energy prior to its unavoidable dispersion. The rationale for this quest for a universal theory does not escape this rule. In other words, a deterministic explanation is we are doing this because we have no choice (despite the appearance of a choice). We are just following the one path mentioned above, the only road possible. That's it. So you are not off the mark by saying 'utility'.