I'm sure many felt the same way about women's suffrage, the civil rights movement, marriage equality, etc. The fact is that the movement to expand rights and equality to all, has always been met with bigotry and hate by those that have always had rights and equality. 

It is offensive to deliberately misgender a trans person because it denies them their identity and agency. I am sure you would be offended if people refused to acknowledge the core of your identity and then proceeded to tell you that you were completely wrong about who you are. I would be voted uncivil if Plainthinker identifies as male but I continued to call you she or her in every single mention of you or response to you, and the more you protested, the more I persisted. No one deserves that treatment!