I'm on my third 3DS, not because they went bad, but because I upgraded to an XL, then to a new 3DS. I sold my old ones to my friends and they still work. I don't know what crap your DS lite has gone through, but I can tell you that I compulsively drop every piece of electronics I own.I keep hearing that, I'm just very fond of the GBA cartridge slot, and how sturdy it is (don't know if I trust a 3DS to endure the amount of crap my 10-year-old Lite has gone through).
At least my two pirate cartridges from my middle/high-school years are long dead, so that excuse to not upgrade is not there.