of the whole matter of pet/human interactions. Anyone who has experienced the evidence of some sequence of say, a confirmed mutual communication
-- especially of an emotional kind and not about some trick -- will dismiss that both cynical and uninformed thesis.
(I could give specific anecdotes, with enough details to demonstrate a level of communication (and empathy!) in some situation/just-occurred,
which could not be mistaken for either 'instinctual engrams' or any variation of 'simulation-for-reward'.)

But when seeking the simplest shorthand, I come back to guilelessness -- that quality noticed to be so alien to so many bipeds
(perhaps because it is the anti-virtue to that requisite canniness? (aka patent misinformation/obfuscation)
-- demanded of all those who would achieve 'Success' in any business-related sense of that vague term.
Animals have not the intellect for relating 'love' to any sort of 'profit scheme' -- is that not obvious by inspection?

How could a one Not-love a guileless creature, given the milieu in which we daily operate?
That this love can be reciprocated, needs no explication for/by those who have experienced it.
But only too-many-words would be required to attempt to dissect and dismember the idea
-- via various anthropomorphized koans, all derived from biped Psych. 101.

I recall a quip by a 'guru' to his students, who wanted to learn about all that metaphysical stuff (and also about 'love'). He said ~~
"You know nothing of love [Love, probably meant, where the capitalization has implications.]
If you want to find out about that, first adopt a pet and find out how to love.
Later, you might then learn -- with enough diligence -- how, someday, to love another person."

Could be something to that.