I am incredibly grateful to Cook for this, not least because of how it will affect young gay people.
When I was a child, I felt generally good about myself. I was reasonably smart, well-spoken, curious, and so on, and I wanted to do something important with my life. Some nagging part of me suspected I was gay from very early on, but I resisted it intensely. I wasn't really afraid of being mistreated, although I probably should have been. People were already calling me names so I wasn't worried about that. More important for me was my sense that being gay meant being marginal.
There hasn't been a gay President, and at least when I was a child there weren't many gay people visible to me at all. The image of gay people presented to me were not powerful, focused on frivolous things, and consumed by attitude and lifestyle. If I wanted to do something important, I couldn't possibly be gay. It just didn't fit.
Knowing that the CEO of not only the most powerful company, but also the most admirable company, is gay would have helped me enormously. I always wanted apple products even before I could afford them, and this would have meant a clearly visible path forward. I can't imagine how happy this must be making some confused young people, given how happy it's making me right now.