I don't much care for a stranger trying to engage in small chit-chat while at the urinal but if it's someone I know, it's no big deal.
This thread reminds me of a seedy little music venue that I used to go to. There were big bathrooms on the same level with the concert-goers. The men's room was just a trough where you had to squeeze in elbow to elbow. But in another section, where the musicians, crew and employees usually went, but not off limits to clients were two single holers. One for men, one for women. The door to the men's room was broken...it wouldn't close. The problem was that it was open to a common area where groupies and crew hung out. You just kinda had to turn at an angle to get some privacy while going. More than once, girls would come in and strike up a conversation while I was taking care of business. The first couple of times it disrupted things, but after awhile I got used to having visitors while using that open toilet.