While it is true that you cannot see who is gay, you are mistaken on your other two points. Just like skin color, sexual orientation (not ‘preference’) is not something that is chosen. It is innate. Also, gay people HAVE had to endure pogroms. During World War II, Jews were not the only ones rounded up into concentration camps. Gypsies and gay people were as well. There are still ‘lynchings’ today (Mathew Shepard) and laws still disciminate against gay people (some states moreso than others).