Scientists compared the differences in genes between friends and strangers across nearly 2,000 people and they found that friends tend to have a more similar set of genes than strangers. Perhaps it's "The Starbucks Effect" -- if two people like the smell of coffee maybe they're more likely to hang out together.
If you make an informed decision to practice barebacking, then so be it. I can't say I will never do the same. However, short-term pleasure, a sense of belonging, and the excitement of abandoning homonormative sociosexual practices cannot be divorced from either a willful rejection of long-term health or a romanticized concept of what HIV infection leads to.