Dupont Circle - Washington, DC 

That is happening in all North American cities. New York is the same, The Village and Chelsea are no longer gay neighborhoods.

How and why did this happen? Is it because gay people don't need safety in numbers like they used to, or is it something else?

I guess the gentrification is to blame!

It still is! Here are some clips from Pride in the hood: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-wzpVPcepCAg.html I would say the main difference is the loss of Lambda Books, which made the LGBTQ presence even more visible. Alas, they, like most independent book stores, are gone.

They all went to Florida cause the area where I went to visit was full of gay and lesbian

why??