Of course I prefer to have the bathroom to myself too. We have two bathrooms in our house and I'll go to the one that's the furtherest from wherever my fiance is, because I don't want to stink it up around him. Peeing, I'll do that in the bathroom just off our bedroom and not even shut the door or care (he doesn't care to do it in front of me either), but when it comes to poop, we both shut the door and go away from the other person. Don't ask me why peeing is okay to do around other people, but pooping is not.
I don't like to go in a public restroom, especially one that contains people I know or work with, but I'd prefer it to be full and busy than to just have one person other person in it. My reasoning behind this is that no one can know where the smell/sound is coming from. Yes, I have timed my poops to be covered by the sound of flushing toilets and running water. And you can always flush your toliet multiple times and it not sound out of place in a restroom that's really busy (unlike when there's only one other person in there).