According to both Pew and PRRI, a majority of Christians in the United States believe that LGBTQ people sin when we have sex. That is unacceptable and evil moral condemnation of innocent members of human minorities. Christians must abandon and fight against that evil and harmful belief system.
One often sees Christians, like they did in the DC riots on 6 January, in an angry froth over LGBTQ people. That's a big problem that isn't going to go away on its own.
Your question about straight people being morally flawed for being straight has an obvious answer: of course not. I can't imagine why you asked the question.
But let's acknowledge something critical and crucial. Christians who believe or teach that LGBTQ people are sinful (immoral) are homophobic monsters - and they are very prevalent in the United States.