It's no secret most of the population is heterosexual. While the LGBT+ population has made great strides in fighting to be seen and heard, heterosexuality is still seen as the 'default' sexuality by the global population.
This means sexual education most likely leaves out most or all educational material which does not involve heterosexual couples or people having a different orientation. School is often a place where new ideas and teachers (and other students as well) influence the ideology of children and teenagers.
Heteronormativity at school is a problem that teaches:
Any sexuality other than heterosexuality is less important.
Yes, this is very, very untrue, but however, schools have not seemed to catch on. This is a very prominent problem that is very eminent in Christian schools, as the Bible (although not clearly) states things against homosexuality (however it may be a mistake in translation).
The ideology that heterosexuality is the main orientation and all children and teenagers should be treated as such, sadly apart from the children/teens who display 'typical' homosexual behaviour (boys liking pink, girls having short hair, which are NOT always true). This also goes for people outside of the gender binary, or people who do not feel like they are a woman or man, because so many people have the idea that there are solely two genders, which is also reinforced by the Bible.
It's okay to dismiss a large group of people.
Over 200,000 years of human existence, we've treated others, the same species as us, absolutely horribly, especially people of colour, which is a problem that while is better, is still not fixed. While there have been some famous people (Lady Gaga, Ellen DeGeneres, Adam Lambert) who have now come out as LGBT+, the community has been and is still being pushed under a rug.
In schools, it is quite the same. By not teaching LGBT+ topics, the community is being hidden, being avoided, much like the 1950s and before. Thanks to many LGBTQI+ groups pushing for rights, the community is now seen, however how long will it be until schools finally take notice?
LGBTQI+ children won't think it's okay to be gay/lesbian/bisexual/trans/etc.
Kids learn most of their knowledge from parents, school and friends. If children who realize they are not, in fact, heterosexual learn nothing or negative ideas about the LGBT+ community, they will hate themselves or believe it is wrong.
They also may not know what is happening to them and be confused. Teaching that the community is valid and perfectly fine is good for everyone, especially the teens/tweens/kids who are questioning their sexuality or gender. It also helps heterosexual children/teens that some people do indeed have a different sexuality, and that's okay!
If LGBT children grow up not knowing LGBT health, it may hurt them.
The highest population of people affected with AIDS are gay and bisexual men. LGBT+ health is not talked about in health class, or if it is, it is usually very minimized. Not learning about how AIDS is transmitted, or how to protect (safe sex is usually also not talked about).
Transgender people are almost never talked about, so people that are might not know what to do. They might never know that binding with ace bandages can tear your muscles. Actual binders are so much safer and won't bruise your ribs! Learning health for everyone can hurt no-one.
As a student and a member of the LGBTQI+ community, (still closeted), I've seen and heard a lot of homophobia, even in my home country of Canada.
- Repeatedly, I've heard people calling each other faggots, which really hurt me.
- Everyone had assumed everyone else was straight, and acted accordingly.
- People judged and were often misinformed with the information they learned.
- Generally, middle school blows, however, me being in the closet while having to hear (I also may have eavesdropped a bit) to all these judgemental and hateful comments made it worse.
- Humanity has always had a case of us vs. them, which got us to today, which is generally hateful. The entirety of people reading this (I think) are humans and we should never solely hate others based on preemptive thoughts.
Overall, heteronormativity in schools is a problem to both the LGBTQI+ community and heterosexuals because not talking about MODERN subjects and issues will not help anyone. The times have changed and we no longer only have heterosexuality. With new subjects comes the need to explain them, and that is what schools must do.