In spite of major strides made in gay rights, surveys show that gay people are still facing discrimination in the workplace and in school. General harassment is an even more widespread problem. This data is backed up by surveys of straight people. Even more disturbing is the fact that some people still believe that being gay is a mental illness or a morally improper choice someone makes. If this is someone's foundational belief, they are likely to pass it on to their children. This makes it very easy for discrimination to continue even in the face of new laws promoting equality.
Unfortunately, discrimination against gay people is still a major problem in America. Gay students are not allowed to bring same-sex dates to many school functions like homecoming, prom, etc. Furthermore, gay couples are banned from adopting children in some states. Some workers have been fired for being gay, or simply being suspected of being gay. In short, this discrimination is still a cause for concern.
Gay people should be entitled to the same rights as every human being, no matter how uncomfortable that makes some people feel. Unfortunately, the problems and discrimination mostly come from those with a more religious upbringing. With some people holding such strong beliefs against homosexuality, the situation is unlikely to change dramatically any time soon.
I don't see the issue, if I came to a homecoming with my dog or a 5 year old kid or a house plant they wouldn't let me, and this is no different. Besides, the school is doing the homecoming, they make the rules, gay people just need to understand that in a "society" sexual perversion is discouraged, if you can't get over that move to a chimp colony.
It really isn't discrimination to L.G.B.T.Q folks. It's just people not agreeing with others' belief. Should you sue your school if they won't let you smoke or drink? No. It's their school, their rules. And by attending that school, you agree to their rules. But also, bringing an opposite - sex person to homecoming has always been tradition. Also, guessing from the term "Homecoming" (And I may be wrong) But homecoming term is usually used at private/religious schools. So it's definitely wrong to sue a religious school for not letting one be gay because some religions don't allow it. There's always a reason behind things and the school obviously had its reasons.
Some people like to think that other people sit around thinking about ways to discriminate against others. The truth is, most people only care about their own lives. Most people don't care what other people do as long as it doesn't affect them. The vast majority of people now support the homosexual community. It's a small subset that don't.