You probably need to try and add a bit more meat to your arguments. See below for a generic 'legal response' to "I'm going to go and attack/kill some Nazis". Because it's lacking in compassion it will understandably rile people up, just keep that in mind... People are raw in the wake of an attack and feeling a lot of anger, upset, frustration and despair. To many, it will feel like you're playing contrarian to wind them up (the violence is NEVER the answer angle), but there are undeniable facts about operating within the law as a civilian and not having yourself liable to face arrest/jail time for violence.
If someone wants to respond to you with fuck the consequences, then all you can really do is leave them be. It's probably just expressing anger and frustration, but if they do actually go out of their home and do anything they are responsible for the consequences they face. Not you. Most people posting understandably rarely say "I'm going to do x", just generic responses they want Nazis put down. As direct "I'm going to..." can get them in hot water for expressing intent, and yes, most people don't actually want their lives to be "over" by going to prison. Instead, it's more a case of "I maybe won't do it, but I won't be upset if someone else does".
All of this is ultimately happening due to where America currently is. You have to be honest and simply accept neo-Nazis walking around with assault rifles in other countries would not be tolerated or accepted. It's just not alright it can happen in America.