There should be no closet. It shouldn't be a big deal, but some people make it a big deal because they are bigoted and hateful. Unfortunately, I can see some redneck NFL fans making it a big deal.
People like their stereotypes. They like to think of gay guys as wimpy, effeminate, and working as a hairstylist or interior decorator. Breaking stereotypes pisses idiots off. For example, an educated, successful, black person used to be called "uppity" because they didn't fit an idiot racist's stereotype.
Same goes for football. The ultimate masculine sport doesn't allow a myopic idiot's view of of where a gay person should have a career. Hopefully we'll see that change in our lifetime, but there may be some ugliness.
So having a few players being gay is "promoting a lifestyle?" Really? This has to be a joke post.