I'm with you OP. I would find it odd and very inconveniencing to the server. We always split the check by number of couples. It doesn't matter who ate or drank what. Generally, we'll all order different apps, bottles of wine, bottled water for the table, so it would be difficult to keep all that on separate bills.
We add in the 20% for tip and split the entire bill 2 or 3 or 4 ways.
I don't think I've ever gone to dinner with anyone who asked for a separate check. At least not in my adult life. But to each their own.