I play more and more of Multiplayer scenarios because of the chat and the interaction with other people. I think its more fun. Of course I haven't stopped playing single players. But I did stop designing a Single and switched over to my first Multiplayer simply because I had better ideas and, for now, I enjoy it more than designing my single player scenario. Of course i'm new in designing so I can't really say witch I like best until I creat more scenarios.
I also dislike Bloods and Massacres. You don't really do anything in them. But there can be very interesting Multiplayer maps, in which no Player has any real advantage by knowing the map better because resource placement isn't that important. I'm sure that resources in EO's upcoming scenario Running Man are usless (but maybe knowing the map gives you a slight advantage,I don't know).
But I do agree that you have far less control of the player. I guess you just have to host your scenario and see how it is played. Maybe it wont be what you were expecting, in a negative way or a positive way.