I discovered a while back that how people see this depends on whether they've only seen the episode or read the Blish adaptation. A
deleted scene from the original script, also present in the Blish adaptation, makes it clear that the spores have a degree of consciousness:
SPOCK
The spores themselves are alien, Jim.
They weren’t on the planet when
the other two expeditions were attempted…
that’s why the colonists died.
KIRK
How do you know all this?
SPOCK
They… told us. The spores have a kind
of telepathy, but it’s subtle, almost a feeling…
KIRK
Where did they come from?
SPOCK
Impossible to tell. It was so long ago and so far away…
perhaps the planet does not even exist any longer.
They drifted in space until finally drawn here…
They actually thrive under Berthold rays. The pod plants
are only a repository for thousands of
these microscopic spores until they find a host.
KIRK
What do they need us for?
SPOCK
There are millions upon millions of them, Jim.
They do no harm… but they want a body.
In return they give the host complete health and peace of mind.
I’ve always been as familiar with the Blish version as the aired version, so I didn’t even realize until a few years ago that the explanation of the spores’ semi-sentience
wasn’t in the actual episode. As Dave Eversole suggested in the analysis I linked to, it gives the episode more of an
Invasion of the Body Snatchers feel than the aired version did. If you only see the spores as kind of a drug, then life on Omicron Ceti III might seem benign, but if you know what the script intended, and what's in the novelization, then it becomes clearer that it's more like enslavement.
But even without that part, I don't think what we see in the episode is benign at all. "Genuine love and respect for everyone under the influence?" No. That's not genuine, it's brainwashed. The spores compel people to try to force the spores on other people. They compelled 429 out of 430
Enterprise crewmembers to betray their oaths and abandon their duties, and almost compelled Kirk as well. Does that sound remotely like free will? Every single person in the crew experiencing a complete inversion in their priorities, ending up behaving exactly the same way as the colonists even though it goes completely against everything they believe in? No — no matter how normal they might seem, this is a complete takeover of the personality, a complete destruction of individual will. It’s exactly the same as Landru in "The Return of the Archons," just without the Red Hour. Anyone who’s not of the Body is compelled to get in line. The compulsion doesn’t have to be violent to be evil. Gentle, tender force is still force. The spores' influence is physical and mental enslavement, the loss of individual choice, freedom, and identity. It's far more malevolent than it superficially appears. That's the whole point of the episode.
It's also the meaning of the title. It's from the closing lines of the poem "
Tiare Tahiti" by Rupert Brooke: "Well this side of Paradise! .... /There’s little comfort in the wise." Meaning that here on Earth, on "this side" of the divide between life and afterlife, there's little comfort in the idea of Heaven, because it's unattainable while we live. In the context of the episode, it means that anything that looks like paradise is an illusion or a trap, because life can never be that idyllic. It's not saying that struggle and striving are preferable to an idyllic, harmonious existence; it's saying that the choice doesn't actually exist.