I find it easier to not have to consider the sexual preferences of my coworkers when I'm interacting with them.
Edit: I should add, if someone is going to attack my character, they're going to do it regardless of what I do. I'm not going to go out of my way to prevent that.
Similar to using encryption everywhere you can: it makes the use of it non-suspicious. The last thing I want is for being alone with a coworker to be implicitly suspicious because the new norm is this sillyness.