Urinal etiquette has changed over the years.
Used to be that it was basically like any other place. Someone looked over at you, or you met them on the way in or out of the room, you either nodded or said "hello" or something in passing, but didn't necessarily start a conversation. Someone made a remark, like "God, it's hot out!" or "Just six hours left to go, until I get home to [wherever.]" You said something polite back, finished your business, and told them "Take care." or something as you left. One didn't take the urinal next to someone else, just so as not to crowd them, unless there wasn't another available, and if so, one said "Excuse me." or something similarly appropriate.
There were rarely, if at all, partitions between the urinals, and sometimes not even between the toilets. Our culture was far closer to the days of outhouses, and, frankly, pissing and shitting was something which everyone did, in an appropriate place, and one just politely ignored it and carried on. Generally speaking, the guys would at least glance at the other guys, more to check out the competition than out of any other interest. Much like in a locker room.
These days, everyone's so horrified at the notion that another guy might catch a glimpse of his dick -- or that he might inadvertently see someone else's (THE HORROR!) that we've skimpy little partitions retrofitted into spaces that were already crowded for us broad-shouldered folk, so that just fitting between some of them can be a pain. (Don't get me started on some of the stall widths, if one's broad-shouldered. I can barely move in some of them, let alone do what has to be done.) Some younger guys are paranoid as hell regarding using the urinals, and will freak-out if someone uses one next to them or speaks a single word while in the washroom. (Some of the "urinal etiquette" pages out there on the 'net are truly laugh-worthy.)
I've never understood why some straight guys have the unwavering conviction that they're going to get harassed, jumped-upon, and/or raped, if some other guy catches sight of their dick. I've often wondered whether it was that they're afraid other men are going to treat them like they, themselves, treat women, but I've really no idea.