its because with cables they stretch over time, plain as that, i dont know why people always go with the spacers, i mean it solves the problem temporarily but does not always fix it, here is what im going to do here soon:
Im gonna take the clutch cable bracket off, drill holes right at the end of the bracket for the bolts, that will give about an inch of play that you can use for adjustment, now here is the second plus of this, by moving the adjustment back farther in the cable you also move the common wear and snap point of the cable which is right where it necks down at a steep angle coming out of the firewall. This should make your cable last longer too, once you start feeling your cable get notchy when releasing or pressing adjust the clutch as necessary to move the worn area away from that point. And by having another set of holes in the bracket that will always leave you room for when you get a new cable you can put it back in the normal bolt holes and then as the cable stretches move it accordingly.
I dont know why some people break more cables than other, i daily drive my turbo sentra and it has an ACT Extreem PP with 6 puck sprung disk and its been in there now for 9 months and im still on my factory oem cable. It streched quite a bit after this clutch went in but has not broken yet, 9 months later, 14k miles later. so yeah i usually just adjust as necessary when the cable gets notchy, so far so good, i have 2 spare oem cables just in case the day comes. haha, i bought those at christmas last year, haha.