It won't happen, they are controlled by the left and the left are currently in power and things are already bad enough without them making things worse.
I hope you're right. But I don't think those groups will see that. The extreme left wing seems to be taking the approach that they have to act now, and this would be an attack against a court that may have a conservative majority for a pretty long time. They must also be concerned that, if 2022 and 2024 lead to a Republican President with majorities in both houses and a friendly court, much bigger changes may be coming. Changes that they will not like at all.
This might be their last real chance to do a lot of damage and unleash violence and destruction with relatively little cost to themselves. That is a very tempting opportunity for a group that believes that their cause is so important that any action is moral and just.