Judy Berman has a post on Broadsheet summarizing the fight to keep "gender identity disorder" from being listed in the newest version of the DSM. The title of her article makes clear what opponents of GIS' listing in the DSM are upset about. The article is called "Are transgender people mentally ill?" gidreform.com's title bar reads "because our identities are not disordered," which I can certainly support in spirit, but not recoginizing gender dysmorphia as a pathology has already had nasty consequences for people needing sexual reassignment surgery in Manitoba, in that the surgery is categorized as being "cosmetic" and therefore ineligble for government subsidy.
If gender dysmorphia is a non-problem, it doesn't need to be treated with expensive surgery. Categorizing transexuals as suffering a pathology should be morally meaningless. If a transexual individual needs surgery to correct a mismatch between their gender and their sex, they have a problem with their original body that can be treated with surgery/medication/counseling - as far as I can tell, what advocates for sexual diversity are objecting to with GIS' listing is the ablist stigma that comes with mental illness. In the real world where transsexuals are subjected to violence and discrimination, it's probably asking a little too much to strike a blow against ablism and homophobia all in one fell swoop. SRS is not a one-size-fits-all solution to gender dysmorphia; plenty of transsexual individuals don't want to physically modify their bodies, so surgery is not indicated in every case. This detail would be crucial to GIS' listing in the DSM
When straight-and-narrow types want to tell transsexuals that they are disordered and should go to hell/the doctor for it, it takes some guts and nuance to say that re-education doesn't "work," but in many situations, gender reassignment does treat the suffering/pathology. This is where the comparison to delisting homosexuality in the 70s departs from the situation with gender identity disorder and the DSM. Homosexuality doesn't need to be/can't be treated with anything whatsoever. Transsexuals who pursue sexual reassignment surgery are meeting physical needs that cissexuals don't have.