I’d think people do hormones and surgeries because they care about that stuff, I doubt they do it for the society. I agree that society shouldn’t care. Like I don’t care how someone walking on the street looks or what’s in their pants.
I do care how I look though. If someone feels they are a woman, they usually want to look like one and it’s hard to accomplish without hormonal changes and often surgeries. Sure one can carry a purse and wear a dress and make up but they might not be happy looking like a man in a dress with a purse and make up (that’s exactly how they’ll look) if they identify as a woman. Now if they are a man who likes to cross dress or dresses as a woman for other reasons, then sure they might not care for hormones and might be ok the way they are. But that’s not who many transgendered people are
As about what’s between one’s legs. I think it’s important for many people for the whole bunch of reasons (even as mundane as being able to wear swim suit on a beach or certain clothes fitting right and then more serious stuff like having certain kind of intimacy etc) . Of course not everyone would care but I am sure many do.
And from what I heard, transgender people often dislike their genitalia and want them to match their gender, it’s understandable. . Heck I am not transgendered and am a biological woman. I sure don’t want penis.