> Are you prepared to follow your reasoning all the way to its conclusion and stop people from having any platform for speaking their mind?

No, that's not the conclusion. The conclusion is that the providers are responsible for it and are definitely enabling it, but sometimes that's better than the alternative. Not everything's black and white, unfortunately.

I'm not entirely certain that unrestricted use of a popular destination is the same thing as unrestricted use of a transport, though, to try and figure out a place where the line should be put. If you have an audience and allow people to reach that audience with dangerous and harmful ideas, that's likely worse than giving them the transport to build their own audience.