Perhaps it’s not easy to decide where the line of legality should go though, which is why this topic is controversial.
It's not easy. Especially when you need to determine what's a controversial opinion and what's hate speech.
For example (and this is NOT anything I agree with)-- if one said 'I don't believe gay people should be allowed to adopt children, because science shows both male and female influences are more helpful when applied together for a child's development' what is that? Is that hate speech because it advocates taking rights away from gay people? Is it an opinion stated with the goal of protecting children?
Does it become illegal to express almost any position that isn't pro-gay?
It's a VERY slippery slope.
Certain speech is criminal like inciting violence. If someone said 'I'm going to buy a gun and kill gay people, and you all should kill gay people too' that is a specific statement of criminal intent and also inciting violence. That will get you cops knocking on your door (and rightly so).
You can apply a 'test' to that- does it show specific intent to commit a crime? Does it encourage others to commit crimes? Yes on both.
But how do you 'test' someone saying they don't think gay people should be allowed to adopt? How do you tell from a few words if they have a hate-filled heart, or if they legitimately think gay people can't provide a loving home? You can't.
For the record- I'm using LGBT as an example. I personally liberal-libertarian--- I believe married gay couples should have guns to defend their adopted children and pot farms from criminals, with single payer healthcare to keep them alive if they get hurt. I'm against almost any effort to take away anyone's rights.
So I'll fight for the asshat's right to say 'fuck the gays' just as hard as I'll fight for the LGBT person's right to marry, adopt, and use whatever bathroom they want (provided they wash their hands).
Disclaimer- in this reply I may use some offensive statements as examples, none of which I agree with. To summarize my actual views- I consider myself liberal-libertarian-- I believe the married gay couple should have guns to protect their pot farm and legally adopted children from harm, knowing that single payer healthcare will prevent them from going bankrupt if one gets hurt. I don't care which bathroom you use as long as you wash your hands. And I think government should be out of the marriage game, there should be a one size fits all civil union for any couple/throuple/quadruple who want to legally entangle themselves (and it should not say 'marriage' anywhere on it). If you want to get married go to a church, if you want to be legally entangled with your partner go to the government.
There's two lines. The line I'm more concerned with (and you should be too), is where's the line between 'simply' a controversial opinion, and 'actual' hate speech. If platforms are required by law to ban 'hate speech' then where does that line get drawn and by whom? And how do you differentiate between a controversial but honest opinion, and a prejudiced and hateful statement, when the two share the same position?
For example, is 'gay people freak me out' an opinion or hate speech? What about 'I don't think gay people should be allowed to adopt children because it could harm the children'? What about 'I don't think gay people should be allowed to marry because marriage is supposed to be a man and a woman'? Are those opinions or hate speech? Is there a difference between 'I don't think gay people should be allowed to adopt children because it might harm the children' and 'I don't think gay people should be allowed to adopt children because fuck the gays'?
Depending on how you define 'hate speech', it might require platforms to themselves remove anything even vaguely anti-gay.
I have no problem with any private platform choosing to adopt whatever rules they want. I have a BIG problem with government-mandated censorship of controversial opinions (and I think you should also).
As for the two lines, let's do a spectrum--- again, this is presented as an example, I do not agree with any of the following statements.
Where do YOU draw the line in there?
For me I'd say the line between opinion and hatred is between 3 and 4, and the line between hate speech and criminal incitement is between 12 and 13.
The problem though is if 'ban hate speech' is codified into law, if platforms are REQUIRED to police it, then ALL of this becomes essentially illegal to say, essentially starting with #1. And while it's sad that anyone would say any of this, that basically makes it illegal to express ANY dislike of gay people because of the murkiness of the line between unfortunate opinion and hate speech.