Well, that's exactly the thing... There's a vast difference between installing some library for a programming language versus an application that John Q. Enduse

Well, that's exactly the thing... There's a vast difference between installing some library for a programming language versus an application that John Q. Enduser wants to use. As far as installing things from source that also has improved greatly in the last two years as well, so there's that. But in general I'd say the user experience when installing applications on the mac is certainly miles ahead of the way Windows typically works, and arguably better then even Linux (Ubuntu or similar) with the gui frontend to apt-get.