The thing is that a rank novice has no idea of what his maxes are at any weight, and as a novice, anything he does at the gym disrupts homeostasis forcing adaptation. So SS is better for a rank novice in that there's only one variable to be manipulated, which is weight. In Practical Programming Rippetoe describes how there's an direct relationship between lifting experience and the complexity of a program because the novice needs less accessory work since he recovers so fast from the main lifts. Since GSLP also varies reps in the AMRAP set, the complexity of the program has been increased and in the case of a rank novice, there's no 5RM to base resets on and there's no max reps to perform because the trainee doesn't even know what his true maxes are.
Like you said, SS has no longevity, but that's by design I think. Anyone who does it for more than 6-8 months is NDTFP, like Rip would say. I mean, Deadlifting 2x a week and squatting 3x when you hit your true 5RM is fucking brutal. After that, it's time to move to something else, be it further strength training or bodybuilding or whatever.
I think that this is the perfect moment for something like GSLP: the trainee knows his body better, he knows what his 5RM looks like, and he is more adept at summoning the intensity necessary for the AMRAP set. Plus, his joints, bones, and CNS are also much better adapted to the higher reps demanded by GSLP.
They are both great programs and honestly so similar that I suspect it doesn't really matter, but I do feel SS offers some slights advantages for rank novices (people who have never touched barbells). It's almost like an algorithm in terms of its efficiency and simplicity.
If I were in charge the university gym I train at (which is filled with skinny wanna-be bodybuilders and skinny soccer players) I'd have everyone do SS for 4 months, mandatory, as is. They don't get to do a single biceps curl until they can at least squat their body weight for ten reps.
After that they'd do GSLP for another four months and then they could do whatever the hell they want. I suspect they wouldn't be very skinny at the end of those 8 months, and the performance of those soccer player would improve dramatically.