"Hate is not an opinion"
Correct. Hate is a human emotion.
The Evolutionary Function of Hate
As such, hate fulfills an important function and has been proven as a protective mechanism over hundreds of thousands of years of evolution.
Hate can derail and hit the wrong targets, but at its core it is important as a protective mechanism against "creeping" dangers.
Acute vs. Creeping Threats
When a fist flies toward someone's face, acute reflexes kick in as protective mechanisms: eyelid closure, blocking with arms, etc.
These natural defense mechanisms are insufficient for dangers that build up over years and require a solution beyond the acute threat situation.
The Role of Hate as a Protective Mechanism
It's surprisingly irrelevant whether it's a crop pest in the Middle Ages or a destructive ideology in the present.
Hate drives people to defensive measures that wouldn't occur in each individual case, but are necessary in sum.
Conclusion
The statement "hate is not an opinion" is technically correct - but it is often used to delegitimize a legitimate emotional response to creeping threats.
Hate is a human emotion with an evolutionary function. Like all emotions, it can be misdirected, but its fundamental existence and function as a protective mechanism should be acknowledged.
The real question is not whether hate is an opinion, but whether suppressing this natural protective response is sensible or even dangerous.