Often, as a group transgender people are allowed to feel like most of the world doesn't care about us. That as humans, we don't matter, and that if something hurts us we should learn to put up with it.
The word "tranny" is pretty harsh for us. It's a slur. To quote blogger Zinnia Jones, "For those not in the know, when cis people use the word 'tranny', they’re typically not referring to us in a kind or affectionate way. It’s vastly more likely to be used as a cheap insult, a threat, a porn keyword, or as seen in this case, a joke unto itself."
Quite simply, it hurts.
By owning up to the fact that a mistake was made in the casual use of transphobic language to promote the new season of Arrested Development, transgender people might start to get the feeling that there are fewer people in the world that see us as just a horrible punchline.
We might even start to get the feeling that the folks who make this show think we're humans.