And HERE the word "queer" is massively accepted as positive.
		
		
	 
Within the American LGBTQIABCDEF..+ community, what you say is probably true. Realistically, that entire population is about 10%. For simplicity's sake, let's call it 30 million people.
Now, to the other 280 MILLION people, "queer" means something altogether different and carries a markedly different tone. "Gay", when applied descriptively, is the go-to, not-terribly-controversial word. 
It can also be used pejoratively. It's also a generic filler for "lame" etc. 
In the context at hand, the vast majority of Americans are probably most comfortable using "gay" as the neutral descriptor (they may well use it other ways too, but as TX-Beau says, what's important is 
intent). "Queer", to the vast majority of Americans, carries a more negative overall tone. As a result, very few non-LGBTQ people will use it confidently in a non-derogatory manner. I'd wager that fewer than 10% of non-LGBTQ people even know that it carries a non-deratogry meaning (when applied to non-heterosexuals). 
Now, let's say one of those 280 million people want to pick a slur they know will cause blood to boil--which one will they turn to? The one that's completely pedestrian and normalized, or the one that's tip-toed around gingerly?
As an in-crowd word, 'queer' is completely fine, but how would you like the entire non-straight population to be referred to on CNN? FOX? Would you be a bit uncomfortable? Maybe it'd be okay if Anderson Cooper used it, but not Megyn Kelly?
If a queer identity is projected (rather than an LGBT one), it's a certainty that it will eventually be picked up by groups that you'd prefer not use it. 
You've given the counter-argument already. That such usage is empowering. Is it? Would you feel empowered if Bill O'Reilly suddenly began harping about "queer Americans" instead of "LGBT people"? (I'd imagine not. Feel free to disagree)
I think it's best to be careful when reappropriating incendiary words. One should never move 'too quickly', lest you lose sight of the people you're trying to convince. It's like teaching; you don't start with basic numerals and the next week move onto linear algebra.