Personally, I don't think birth certificate should be changed at all, you were born a certain body, can't change the past, but do think that there should be something still to show that those that have gone through sex reassignment surgery are indeed no longer the sex they were born as, and therefore accepted in place of original birth certificate. But if you haven't, and still have your birth parts, no way, you still got a penis, unfortunately still a guy in body even if not in mind, because society only looks at the physical aspects, same if born with a vagina. So much as I'd like to be viewed completely as a woman in every way, including legally in documentation such as birth certificate, or even I.D., its not possible with my wrong parts, and I completely understand why.
Does it bother me, of coarse, but I'm not going to make a big stink about it, but hearing that some other can, and one that doesn't even have any desire at that to be the opposite sex can do so, this just pisses me off. As is, because I'm unchanged down below, I have to live with an 'M' on my I.D. as a constant reminder that I don't fit in as a genuine woman. It has always worried me to show my I.D. to anyone because of that 'M'. Oh, but this past I.D. that I had renewed, the clerk wasn't paying attention, she instead of reading everything on the application as well as my old I.D. just made assumptions, she saw me as female, which is no wonder I wasn't asked for all the usual stuff, proof of my existance, being transsexual, and was surprised, pleasantly so, when I got my I.D. in the mail and it showed me as 'F', female. I wasn't about to show them the error, their screw up, not mine, but I bet next time it'll be changed back to 'M' once they realize their error. At least for now I can feel more comfort in that if someone sees my I.D., I won't have to explain anything. I'm a woman, but still legally, only in my own mind, not in body, therefore not a woman.
If everyone was able to change their birth certificates so easily, changing on there their sex even when sex hasn't been changed, it'd get pretty messed up, such as one who is clearly a man, just likes to play at being a woman sometimes yet still enjoys being a man, still gets off like the average man, still enjoys women sexually, able though to get birth certificate changed for whatever excuse given, now uses women's restrooms because he is deemed a woman legally even though not, not even in mind, then women are uncomfortable because of possible pervertism (yeah, the guy jackin' off in the next stall over, eew). Its different for those that are transsexual, we, even though not physically, are the opposite sex of that which we were born as physically, we're just looking to fit in, no harm intended towards anyone (other than ourselves at times), and here even with this, we have a hard enough time with changing even simpler documentations, such as I.D. or driver's license, because we aren't physically therefore would be considered fraud, even if not intending to for any reason other than to protect ourselves.