I can't help but think we are reaping the results of the "sexuality is innate and unchangable, the science says so" approach, which has been very doninant in gay rights from the 80's.
The thing is, we don't really even have a very good scientific definition of "sexuality". The idea that we can say that homo, hetero, or bisexuality are somehow fundamental and natural in either sex, or that these are set before birth, or not culturally influenced, and all the rest - it's just not supported scientifically.
Sexuality is to some extent, and we don't really know how far this goes, a constructed category, and one that isn't particularly historically common.
It's very difficult to "prove" that things like AGP don't belong in the same category when you don't have a clear, evidenced and explained set of criteria beyond "this is how people experience their sexuality whatever the heck that means."
Rights groups chose to run with this idea because it was very successful at creating empathy in the general public. Not because it was the only compelling theory or because it had the best evidence base. So finding that now there are other theories without compelling evidence that people expect to be supported for their social utility, as they see it - well, yeah. That's the precedent that's been set and a whole generation has been taught that is the only moral way to think about issues.
These seemingly small fudges for the greater good bear fruit down the line.