UJM, I never heard that before, but it could still be true.
UJM, If you want us to accept what you just said,
then you must give us the exact source where it is located.
Until then, you might be interested in reading these two
definitions of Sinat Chinam, that I researched a long time ago:
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Tehillim, chapter 69, verse 5:
“Greater than the numbers of hairs on my head,
are those who hate me without cause…”
Metsudath David on this verse explains:
people hated him [David], even though he never harmed any of them.
If I read this Metsudath David correctly, he seems to imply that
the definition of Sinat Chinam is hating someone who never harmed you.
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Rabbi Binny Freedman said:
The Talmud tells us that the second Temple was destroyed
through blind, wanton hatred, or sinat chinam. It is difficult
to understand how any hatred can ever be chinam,
which seems to mean “for no reason at all.”
The Netziv suggests that this wanton hatred refers to
disliking or even detesting someone because their views are different.
SOURCE: article titled: “Jewish people have a different set of priorities”
by Rabbi Binny Freedman, 2022 July 13, www (dot) TheJewishStar (dot) com
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If anyone has more definitions of Sinat Chinam,
with exact sources, then we are all eager to read them.