The term character has a loaded meaning when speaking about it in most cases. Usually, when we think of characters, we think of individuals with unique motivations or direct quotes. This understanding just would not work when assessing the force since individual motivations, direct quotes/actions would be quite inappropriate for something that is tier 0. To use an example, the Force is closer to "God" from Unsong, the Divine Comedy, or World of Darkness than it is to Goku (To clarify, when I use these profiles as examples, I am bringing to light their role as some sort of fundamental, transcendental source within Star Wars, not directly referring to the Force as a God which is also considered a misinterpretation addressed in the justification paragraph). It is also seemingly not a location or merely "some force" (which is ironic given the name, of course). When we are talking about Tier 0 things, oftentimes, traditional character traits boil down to nothing. When we're talking about tiering the Tier 0 Force, we're talking about some source that is not just a cosmic phenomenon or energy field, as these are only the interpretations that other characters in-verse impose on it.
It is closer to some "conceptual entity" than it is to the traditional character, which I think is quite the unfair standard to hold it to if we already acknowledge that it is Tier 0. Other tier 0s, as listed in my example above, also fit this distinction much closer than they fit being a traditional character in my view. I am not against giving it a tier at all.
To quote the proposed justification that was accepted in the Tier 0 CRT:
"The Force, in it's most utter simplicity, is a unifying oneness fundamentally distinct from any and all interpretations and conceptualizations imposed upon it, which do not truly grasp The Force, but rather the limited understanding of mortal beings of what it is, whether it be as a non-sentient energy field, midi-chlorians, the universe, or even god itself, they are all "half truths" or "lies", which will always be inferior to the truth; the truth that "All is One", that The Force is devoid of duality and distinct parts other than itself, as The Force is everything and everything is The Force, and all that is or evil will be will eventually return to it's oneness beyond qualitative separation and differentiation. Whether in Beyond Shadows, where reality beneath is simply a dream, or in lesser planes of reality, The Force is binding just as it is everywhere else. It thus cannot be separated or differentiated outside of it's non-indicative interpretations and conceptualizations."