No they haven't. On the 'Steve Jobs' versions of OS X updates never needed a restart, such versions as Leopard, Snow Leopard and Lion. The only exception was on major updates where a DVD was required for the update.

They even used to use that it used to do this to bash windows.

The 'Steve Jobs' OS X versions were very refined. Somewhere around Lion everything went downhill. Mountain Lion's flaws were slowly more pronounced.

It also used to be than a new OS X version used to be faster despite it running on the same hardware. Its hard to say if this has changed.