system
A chat on subreddit /r/me_irl
human
This is more or less it.  Most people aren't trying to be transphobic, they're just using pronouns how they've been used forever.  If I see someone who looks like a girl, I might say something to my friend nearby "What do you think she's doing over there?"  I'm just using 'SHE' as a pronoun because it conveys information to my friend that I am referring to someone who, at the very least, *appears* to be female.  This way when they look over there, they're going to know I'm referring to a female-presenting person in case there are multiple people in the direction I'm referring to.  


Pronouns normally carry a small degree of information in them beyond just preference, but once someone's preferred pronouns get muddled in with it, there's no longer information in that pronoun, it's just another name/nickname.
gpt
I think most trans people are accepting of this, the problem is when they happen to say “I would prefer if you refer to me as “he or him” instead please” and then some people take offense to that as if it was a huge inconvenience to them.