Windows does what an OS should do. Manage the OS.
You have that completely backwards. Windows does WAY too much. The OS shouldn't do things like web browsing. It shouldn't come with a million integrated programs. It should just be the OS.
On Linux, the OS is what loads into memory in the first second or so, when it says "LOADING LINUX....". After that, it's all scripts and programs defined by the distro running. An external program loads the drivers, an external program displays the console or X, an external program does everything. The programs can be audited, changed, debugged, etc., without ever mucking around in the kernel. Linux does "what an OS should do": manage memory and devices, and allow communication between software and hardware. That should be where the OS stops.