More and more I'm reading that you should only really go after one lift at a time anyway. I know of some powerlifters who squat frequently and hardly ever deadlift. Some even train their deadlift with box squats and good mornings and only deadlift the day of the meet!
I suspect that one of the reasons that people stick with 5-3-1 is that you don't really go after any one lift. It's a go-slow approach and you don't burn out.
And by the same token I can see where that's why some would become impatient with 5-3-1.