"The swastika on my forehead is a symbol of love and peace. How could you be offended?"
If it's turned a specific way, it is the Nazi symbol. In Asia for instance (where I lived and studied for 5+ years), you will see the symbol all over the place. It is still a Buddhist peace sign in many other parts of the world and in fact, I have purchased multiple items online (and on Amazon) with the symbol on it.
I know plenty of people that purchase Chinese new year decorations and put them in their car with that symbol.
So, your example is flawed.
"The Confederacy surely did exist primarily to promote slavery"
No it didn't. It existed to promote states' rights. Slavery is one of those rights (and the one brought up the most).
"This is certainly true in some places, but not everywhere. You see plenty of Muslim women in, e.g., the U.S. who do not cover their head"
You also see plenty of people with the confederate flag that do not support slavery. This is my point.
"And, in any event, this doesn't establish that Islam exists for the purpose of subjugating women to anything like the extent to which the Confederacy existed to promote slavery."
I don't see people with confederate flags creating laws that force African-americans into slavery. We do have examples of countries that force women to be partially covered (and in some instances, completely covered) and other extremely harsh laws like stoning if a woman gets raped (this is a real law btw.).
But it gets the magic pass, even though in some instances, supports the most vile and terrible human behavior.
So you support symbols of a religion that do in fact put people into slavery, by law. But you don't support a symbol that has done nothing of the sort for 100+ years.
"Google it. This is blatantly false."
This is the first time I've seen it on CNN or any main stream news site (and I read lots of news every day) and it was only after this incident that government officials needed to do anything about it. It must not have been a big deal before this incident.
*edit: This is why HN group think (and group think everywhere) is dangerous. I am trying to have an open an honest discussion about politics and I am silenced immediately.