Also in terms of mckmas8808's post:
"but it seems like if you are a minority or LGBT, your very existence is a liberal agenda to some people!"
Exactly. I think some people are ridiculous in how hard to make sure a non-white character (or non-straight, or even female sometimes) "makes sense" in the story (not counting specific historical stories, I can understand why a Hispanic guy playing a large role in an American Revolution film would feel out of place) and "how well they are written" but white characters (and males, and LBGT) are almost never given the same scrutiny by these certain people.
Like, hey, we got a future sci-fi show with a rag-tag group of adventurers. There's two white males, a captain and his main buddy, okay no need to examine them anymore, they're automatically good. A white female character, hmm okay, but she better not be "too competent", we'll likely not notice the guys displaying the same amount of skills but we got to examine her every move. A blue-skinned psychic alien character, yeah it's sci-fi, that works. A black guy and a Hispanic woman, hmm getting a little too diverse in here! Well, rest assured I'll be scrutinizing their character arcs very closely to make sure they're not just "thrown in" or something. I may not give the same amount of scrutiny to the two white male leads (and the alien, well unless he's Jar Jar Binks-level of bad, we all have standards) but we know white males are never "thrown in". Huh, a gay guy, oh come on. What are the odds of this small crew having a gay guy, I did the "totally accurate" math and that's really pushing it. I can fully accept the blue-skinned alien with three eyes and psychic abilities I mentioned earlier, but a gay guy is so out of left field! Well, as long as it's not shoved in our face or anything. I mean, the white male captain can bang all the human women and alien women he wants, but the gay guy, err, tell you what we'll let you have an off-focus kiss near the end of the series, mkay? Don't want to seem "political". Also, the boyfriend will also have to be white (or alien, because they get a free pass apparently), if he's black or Hispanic or so forth then that's too much. A gay couple is already a lot, an interracial gay couple, come on. I mean, I clearly know that would be pushing an agenda, it's not like the actors might simply have had solid chemistry together or something.
To reiterate, this does not apply to everyone, but there definitely are people who basically behave in the way I displayed in the above paragraph.