I love the terminal and use vim as my primary text editor but I can't remember the last time Mac OS full-screened an app for me unless I told it to. I drive most of my mac through keyboard shortcuts and minimal pointer interaction. Perhaps a mouse-first Mac users are forced into full-screen? That still doesn't sound right though.
It doesn't force applications to be fullscreen, but it does have garbage tooling for managing multiple windows on the screen simultaneously. Even windows has better with hotkeys and gestures for snapping to parts of the screen.
Mac OS originally didn’t have the concept of full screen (expect for games, pro software) or tiling. Its floating, overlapping and spatially oriented windows blew people's minds. It was coherent and wonderfully executed, both powerful and simple, I miss it dearly.
During the OS X brain transplant and particularly after Lion it became a hybrid that’s neither here or there, unfortunately.
Sadly by the looks of some of the replies here, never will recover from, since people seem unaware that it never used to do that, and would delightfully size itself to the content. This is the #1 feature that I really loved about Mac OS window management.