You are right.
We should not forget the "'diplomatical' benevolence", that underlies the meaning of metta.
The "contract of friendship" between all beings.
(extracts in the suttas with parallels, concerning metta).
If only this world could be shared wisely by all "beings"*.
(see extracts SN 20.3 and SN 20.5).
Metta is really something that some beings should put genuinely in practice.
In the meantime, I'll try to protect others, and protect myself as well.
I 'm sure I can find some unrepulsive in the repulsive.
This last line would be my "Invocation for Harmony".
Is all this too "irrational"?
Karuna, karuna for this lost generation - Again.
“Having realized by his own direct knowledge this world with its Devas, maras, and Brahmas, this generation with its ascetics and brahmins, its devas and humans**, he makes it known to others”.
“…there are in the world ascetics and brahmins of right conduct and right practice who, having realized this world and the other world by themselves, by direct knowledge, make them known to others.”
**I suppose that the Buddha did include, in the lot, the "privately initiated".
"Privately initiated", what an idea.!?! - Why not relying on the Buddha Himself; and just discover by oneself?
Some working for the Mara's world; some for the Brahma's world; some for the Unborn.
In this world with its ..., māras, ... in this population with its ascetics.... (AN 5.30).
We are all possessed - more or less.
And what, bhikkhu, is inward rottenness? Here someone is immoral, one of evil character, of impure and suspect behaviour, secretive in his acts, no ascetic though claiming to be one, not a celibate though claiming to be one, inwardly rotten, corrupt, depraved. This is called inward rottenness.”