I suppose a few arguments would be that we're very much for discrimination, and that we support a lifestyle that is less "free" in a way. The movement also contains people who are outright hostile to anything that isn't them (but what movement doesn't have these people?), and this results in the alienation of otherwise fine allies.
I would also argue that there are those in the movement whom are far too critical of Jews and non whites, which we should be critical mind you, but certain folk take things a bit too far and border on fanatism when it comes to their distrust and even resentment of Jews and such. Mind you they have a valid reason to be distrustful, and worry we'll tone things down and dilute the movement, so I just try to turn a blind eye to the particular crazy people and focus on the 14 words.
Let's be honest, we aren't beyond critique, but from where I stand there are few negatives. Some argue the the Alt right will divide people, but I think it's obvious that people divide themselves, we just acknowledge it. I think the world can come together and respect ethnic and cultural boundaries, and that's worth breaking some eggs.