The HRC’s official statement on the matter is that the 2007 decision was a “one time exception” made because of the political climate of the time and the belief that ENDA would pass with sexual orientation defined and the trans protections left out. Though they have been lauded for this new development and the fact that they've rescinded their original policy, the memory of their 2007 stance is still fresh in the minds of many, and is symptomatic of a major rift in the LGBT community between the LGB and the T.
Within every social movement and political movement there are lines drawn and loyalties defined, and inevitably someone is left out or seen as expendable. In this case the transgender communities felt betrayed by the HRC’s refusal to push for inclusion in ENDA, and as in this case very often the ones who are left out are also the most vulnerable. This was nearly the case in the Women’s Rights Movement and the push for the Equal Rights Amendment, and lesbians almost found themselves thrown under the bus for the sake of political advancement, though it was thankfully averted at the last moment, and perhaps because of that the Amendment died in the water. And now some gays have similarly turned on the trans community when passage of ENDA is so close, but it doesn't have to be that way.
A way of understanding this phenomenon can be found in the social order theory, which states that certain groups move upwards as they gain more prominence and acceptance within society. I grew up near a town that was a perfect example of this theory in action: The top of the hill was the most desirable place to live, and through the decades the ethnic makeup the area changed from white Anglo-Saxon Protestant to Catholic and Irish and later people of color, first wealthy African Americans and then Asians. At the moment the people below the hill are mainly Hispanic and Caribbean, though some of them have begun to advance up the hill. Within that town we see a snapshot of American culture and cultural acceptance, with those at the top of the hill being “true” Americans while those below are still struggling to assert their place within our society.
The state of the LGBT community can similarly be seen as tiered. At the top are “regular” gays and lesbians, people who can “pass” for straight and are seen as culturally acceptable by Americans who don’t mind a gay person as long as they “act straight” (note the quotation marks in the last sentence and throughout this article). This is the type most commonly seen in the media and the least likely to arouse extreme hatred. Following these are the ones seen as flamboyant or behave outside their expected gender role, and in this level the possibility of retaliation is much higher, and jokes and stereotypes about this group are more widely accepted. Following them are bisexuals, and besides facing persecution within the LGBT community, many people still doubt the existence of true bisexuality and not just “confusion” or “indecisiveness”. This is also expressed in media, which has a continuing reluctance to accept that some people are attracted to both men and women and are under no obligation to "choose" a "side".
We then get to the T, and even below them are the Is, the Intersexuals. While it can be said that most people have at least a passing familiarity with the concept of transsexuality the same cannot be said of Intersexuals, who sometimes find themselves subjected to persecution by transsexuals. No one is talking about intersexual rights at the moment in any national venue, so instead it's the transsexuals who most often find themselves left out and discarded for the sake of “advancing the cause” and securing rights of the “majority”.
Perhaps in the case of transsexuals (and by extension, intersexuals) a certain amount of this can be attributed to just how deeply rooted the concept of a binary male/female gender system is, so by extension those who cross gender lines are seen as a threat by people who might accept gay men and women as long as they act like men and women respectively. Mainly, though, this can be seen as another manifestation of the social order, and the desire for one group to advance itself even if that means sacrificing some of its allies.
This is in no way meant to excuse that behavior, as I said the most unjust part of this is that those who are the most vulnerable are the ones left behind, but it is simply in the nature of our current political system for the fringes to be discarded. In presidential elections both parties will attempt to distance themselves from the far right and far left once they clinch the nomination in an attempt to reach for the all-important center and the majority in the national election. Any group that enters the national stage will eventually do this, but in cases such as this the abandonment of the vulnerable should rightly be thought as sickening and threatening to the very purpose of the group itself, which is to ensure protection for all people regardless of any personal qualities or identity. What the HRC did in 2007 was a betrayal, plain and simple, and though they are now making a valiant attempt to rectify it the memory won't fade any time soon, and the HRC's reputation will remain low within the LGBT community until they show that they will not do this again.
I end with an applicable and well-known quote from Benjamin Franklin:
“Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety.”