Let's talk for a second about the truly generic systems: Hero, GURPS, FUDGE/Fate, Cortex (I gather; I have never seen it).
What most "universal" or "generic" RPGs bring to the table is a rule set that establishes what amounts to a "physics engine" -- that is, a set of rules about how the world and the people in it work. Now, they aren't without stylistic input -- GURPS makes a bunch of assumptions about tone that are different than Fate's assumptions, for example. But by and large what they are trying to do is establish a baseline for interpreting the "reality" of the game space and thereby giving the GM and players a common language from which to build the story of the game they are playing. This, by the way, is why I put D&D in the broadly "generic" category: it is all about providing a common language from which a wide variety of game styles can emerge (as someone said previously, you can run Greyhawk and Spelljammer in D&D; it can't be that bespoke).
I used to be really into the Hero system, but that was mostly because of Champions. So Hero wasn't, for me, a truly "universal system." Even so, i read enough comics to know there were many different styles, tones, themes and even genres under the umbrella of the "superhero genre." So, by that definition, even Champions (as opposed to hero) was a generic system. You could build it to do a very specific thing, and then re-build it to do a different thing.
What most "universal" or "generic" RPGs bring to the table is a rule set that establishes what amounts to a "physics engine" -- that is, a set of rules about how the world and the people in it work. Now, they aren't without stylistic input -- GURPS makes a bunch of assumptions about tone that are different than Fate's assumptions, for example. But by and large what they are trying to do is establish a baseline for interpreting the "reality" of the game space and thereby giving the GM and players a common language from which to build the story of the game they are playing. This, by the way, is why I put D&D in the broadly "generic" category: it is all about providing a common language from which a wide variety of game styles can emerge (as someone said previously, you can run Greyhawk and Spelljammer in D&D; it can't be that bespoke).
I used to be really into the Hero system, but that was mostly because of Champions. So Hero wasn't, for me, a truly "universal system." Even so, i read enough comics to know there were many different styles, tones, themes and even genres under the umbrella of the "superhero genre." So, by that definition, even Champions (as opposed to hero) was a generic system. You could build it to do a very specific thing, and then re-build it to do a different thing.