ok, as suspected you are underestimating the scope of the invention and reducing it to a tiny feature of it.
the patent deals with what it is, how it interacts with running and exiting applications, how the user interacts with it, how it can be configured, in what ways it can be configured, even the start menu and a plethora of other things. it is an invention that can be patented and was granted a patent. was not even controversial. you don't need a blue led type breakthrough to patent something. if you can't see how coming up with all of the above from a blank slate and iterating on it until it fits with the system and user expectations to become the most successful UI innovation ever (remember, something that obvious was mysteriously not present on earlier systems, even when they supported multitasking) then again, I don't know what to tell you.
I'm not sure what you mean by not present in earlier systems.
Windows 3.1 had minimizing programs' icons in bottom-left corner of the desktop, and so did NextStep, and similar icon space can be traced all the way back to Windows 1.0.
Extending that to all running programs and/or dedicating an always-visile area doesn't appear to be as fundamental a you want it to appear. Integrating it into the OS is obviously not meaningful part of the innovation as Windows approach would not apply elsewhere.
The essence of it is someone having an idea that all program's icons should be always visible on the screen, the rest is implementation, and ideas shouldn't be patentable. I'm also pretty sure adding a task bar to KDE/Gnome was done not by reading the patent, but rather by implementing this basic idea from scratch.
Going back to blue LEDs, it's as if the concept of a blue LED was patented itself, and nobody could do a blue LED with a different kind of semiconductors and doping.
the patent deals with what it is, how it interacts with running and exiting applications, how the user interacts with it, how it can be configured, in what ways it can be configured, even the start menu and a plethora of other things. it is an invention that can be patented and was granted a patent. was not even controversial. you don't need a blue led type breakthrough to patent something. if you can't see how coming up with all of the above from a blank slate and iterating on it until it fits with the system and user expectations to become the most successful UI innovation ever (remember, something that obvious was mysteriously not present on earlier systems, even when they supported multitasking) then again, I don't know what to tell you.