No one should get mad at the ACLU for doing its job. Just a month or so ago, people were praising them because they sued the Trump administration for something. They do great things that are more important. Defending Milo doesn't even mean anything. The dudes career is dead. No reason to hurt the ACLU for defending his rights when they are sometimes the only people defending justice.
Also, in regards to restricting Nazi free speech, Germany and other places can do it because they have strong educational support structures and national movements against these things. In the US, we just don't have that. 30-40% of the country thinks of people like Robert Lee as a hero, and the confederate flag as heritage. A Texas school book, just a few years ago, called slaves, "workers". The failure of reconstruction is no more evident than with the number of people and Fox defending the Neo Nazis against the "evil" BLM protesters!!!! Even after they killed people. Sorry, but if you restrict their speech, you are just going to embolden them. Unlike other countries, they don't just have just little groups they can run to when they get hurt, they have states and cities, where their hatred will fester and grow and become worse. People are already comparing BLM to Nazis, and the first thing to happen to BLM after a law that restricts Nazi speech, would be a law in Alabama restricting BLM there for the same reason. I just dont think its a safe path and doesn't do much to curb anything unless there is a real support structure to ensure people get the right message. Like a second reconstruction.