Trolls, agitators, radical trans activists, poseurs, and untreated mental illnesses. This wasn't a problem when transgender referred to people who actually have gender dysphoria to the degree that medical transitioning was necessary to feel comfortable in their own skin and resulted in them successfully presenting as their desired gender. Back then, a transwoman (or transman) would go about their day and no one was the wiser and they certainly didn't make a point of letting people know they're transgender.
This current discord has all come about since the trans community has been infiltrated by ideology and morphed into a political movement. Now, you don't need dysphoria to be trans, much less be on cross-sex hormones or make any effort to present as the gender you're claiming. Hell, you don't even need to feel male or female despite that being the crux of wanting to transition. And if anyone says anything, just scream bigotry. Social media fuels this since we're in the era of narcissism and clicks. There is no shortage of people online who are obviously male causing a ruckus because they were "misgendered" or someone had a problem with a burly man entering women's bathrooms.
This video gives a good overview: (warning: language)