I would say it's not.
You can't apply logic to something where it cannot be applied. Concepts like Gods and Spirits, by their very nature, live beyond our own realm of existence. Maybe Native Spirit animals don't exist, Maybe Christian God or Islamic God doesn't exist, maybe the Greek Pantheon doesn't exist, but you cannot concretely prove that Spirits, Gods or a singular Creator does not exist.
In my mind, it's not intellectual cowardice, it's simply realizing that logic cannot be applied to something exists beyond its realm. Calling it fence sitting is totally wrong, at least to me, because I have chosen a place to stand, that there is no real way to know.
many people in the past have dabbled in Magic rituals, and have come to supposedly become briefly clairvoyant, or had encounters with angels and demons. We only have the first hand accounts of the people engaged in the ritual, maybe they really did contact magical entities, however on the flip, most often they had run their bodies dry through fasting, sleep deprivation, ingesting toxins, and drug use. was it just an hallucination, or did they really contact the 'other side', or some strange combination of the two?