Agreed! Call me old-school or whatever, but I've always loved the Superman/Lois/Clark love-triangle, and also the banter and rivalry between Clark and Lois.
But most people seem to like the fact that Lois knows that Clark and Superman are the same person in MOS. As you said, for realism.
Well I don't think it's for realism. I think it's for a different story. The relationship story can still be great without the triangle. I'm glad they went a different route because it's tough to watch a story when you know how it ends.