Wedding planner seats guests alphabetically by first name, separating them from their dates: 'One table was pretty much just women named Sue/Susan/Suzanne who didn’t know each other at all'

Going to a wedding is a big social event. Sure, you're there to celebrate the happy couple, but you're also there to hang out with all the other guests. Actually, that's mainly what you'll be doing since the couple is probably going to be busy. You have to spend the whole (usually all-day) affair with a bunch of people you may or may not know. Maybe there's a group of your friends who are all going together, and you can all sit together. Or maybe you're just a plus one and don't know anybody else there. You hope that when you see the seating arrangements, you'll be at a table with people you know. 

That's the general expectation. In deciding where guests are going to sit, the couple and the wedding planner usually try to make everybody happy. You seat family with family, friends with friends, and enemies across the room from each other. But at this wedding, they did things a little bit differently. And like all weddings that do things a little bit differently, people had a lot to say about it.