No, it's not completely opposite. You can see UNIX as a simplification of Multics (with the name being a very nice pun!), dropping most of the really hard-to-implement features and focusing on a simple core. Ken Thompson and Dennis Ritchie were programmers on Multics and they admitted lifting features from Multics to implement UNIX.

Many of the things that Multics had eventually made their way back into various UNIX derivatives, because they were great features that a modern OS wants to have. Multics was way ahead of its time in many ways.