For centuries, humans have loved deplatforming. We've developed many unique, hilarious, horrifying, explosive, and even stupid ways of deplatforming.
These include defenestration; trap doors beneath the hang-persons' nooses; or should that fail, kicking a chair out from underneath a condemned prisoner; channeling one's innermost Ayn Rand and blowing up all the buildings; firing cruise missiles at oil platforms, banning Nazi newspapers...
Yet Western humankind's current preferred deplatforming methodology is simply screaming "Don't give them a platform!" at other people's faces.
While it is sometimes well intended, deplatforming often has poor outcomes. In the case of oil platforms, it's super bad for the environment and you get sticky feet at the beach afterwards. In the case of Nazis, it helped them grow faster and probably helped them become more evil...
Even defenestration has it's potential downsides, such as expensive window repairs.
But this blog post isn't about throwing people out of windows or blowing up oil rigs. Or at least it mostly isn't. It's about lefty-Staliny-handwringy "Oh no! The meanie said a bad hurty thing so we must protect the vulnerable from the bad man!" deplatforming. Dare I say it, it's about banning "hate speech".
I get it. Your intentions are good. Few people enjoy being insulted. Some are able to kind of enjoy it in some ways, by laughing it off/mocking it... Others perhaps not so much. That is particularly so for those who are more socially vulnerable than other people - it's much less likely that a disabled person, who is an immigrant or refugee, for whom English/other Western language is not their first language, will have quite the same fortitude as, say, some rich white arsehole.
Add to that, the Christchurch terrorist - "Pouty" - committed his murders in Mosques, not boardrooms... That plays out throughout the world essentially all the time... It is absolutely true that those of us who are minorities or more vulnerable for any particular reason are vastly more likely to be the victims of such horrific crimes.
As such, wanting to protect such a vulnerable person is thoroughly praiseworthy - so well done you.
...But "deplatforming" is not the way to do it. Not because of any philosophical "free speech" reason (well, OK, sort of also that), but because it just doesn't work. In fact, it can have the exact opposite effect of that which you intended.
Deplatforming a Nazi does not make them no-longer-a-Nazi. It just makes them a Nazi that you can no longer see or hear, as they're not on a platform. At least, they're not on your platform - the Nazi definitely remains on their platform among other Nazis. Only now, they've got an oppression/Martyrdom narrative to use to whip up more resentment among those who listen to them. This is precisely what occurred in 1933/1934 with exactly Hitler.
"Deplatforming" Hitler following the Beer Hall Putsch trial became a propaganda victory for the Nazis. Time in prison gave him an opportunity to write Mein Kampf. Deplatforming spread the Nazi message far further than not deplatforming him would have. It also made him harder to notice and monitor.
These same things can occur again in the current era if we are not careful... But I think by far the greatest risk posed by "deplatforming" is the risk of inadvertent amplification of suboptimal messages promoted by utter bastards.
Somewhat related example - Streisand effect. If that made you think of an aerial shot of Barbara Streisand's house, it's because Ms Streisand attempted to suppress (or deplatform) photos of her house. The reason for the name of this effect is, hopefully, self-evident. Note that I'm not passing judgement on Ms Streisand whatsoever. I have few thoughts or opinions about her at all.
Compare that to Bob Dylan's house. Do you have any idea what Bob Dylan's house looks like? If you don't, you aren't alone. I don't either. That's probably because Bob Dylan has never made a gigantic fuss about wherever his house is and whatever photos there are of it. I'm quite the fan of Bob Dylan... And I'm not a fan of Barbara Streisand at all... Yet I can clearly picture Streisand's house, while I have no idea what Dylan's house/houses look like.
So in summary, that's why you should consider your options carefully before you fire cruise missiles at oceanic oil platforms. The end.