I just didn't think that the physics community had enough of an understanding of the nature of Time to rule it out as a force.
I'm going to drastically oversimplify, which I hate:
Forces in physics mediate interactions. In most cases forces are simply useful ways to look a specific kinds of interactions among/between bodies or particles or what have you that are not "fundamental" in the sense that they emerge from more fundamental interactions acting on bodies. Friction, for example, is a force, but it is not fundamental because it can be better explained in a fundamental sense in terms of much smaller interactions among systems composed of many particles.
Even in the fundamental forces there exists redundancies. The electroweak lagrangian (theory) is already a unification of electromagnetism and the weak force, and electromagetism is not the EM you learn about in classical field theory or an E&M course (for one thing, even classical magnetism is a derived "force" due to relativistic interactions). The forces themselves are "composed" of kinds of particles of sorts (bosons) that mediate interactions among so-called fundamental/elementary particles, so that
1) The distinction between forces and the things they act on becomes blurred at a fundamental level, making forces more of an organizing scheme
2) Mediation is attributed to kinds of particles (like photons in QED) that become difficult theoretically/phenomenologically from the mediating "particles".
If it helps, in a sense time is a "force" in that, because our best theory of gravitation is the dynamical local interaction between spacetime and mass/energy, and time is a component of spacetime, time is kind of a modern "classical" force we are trying to make consistent with actually modern "forces"
That said, time is usually either a parameter or a coordinate in the space in which interactions take place. It is not a force for the same reason a different spatial coordinate is not a force. It is the background space in which forces and the things they act on interact, not something that determines/mediates such interactions.