You’re 16. You’re a Pedophile. You Don’t Want to Hurt Anyone. What Do You Do? (medium.com)

The difference between the two is that homosexuality can be acted on between consenting adults. One can argue about exactly what the age of consent should be (18? 17? 15?) but it's difficult to argue that the difference in levels of maturity and in control over ones own life between an adult and a young teen makes their relationship sufficiently unbalanced that it can be impossible to prove that there is no coercive element. And pre-pubescent children are not emotionally mature enough to engage in sexual activity with full understanding - most would not choose to voluntarily and those who do participate even without coercion are typically traumatized.