Much like a computer if its crashing its most probably user error, and if you leave apps running in back ground it is going to be glitchy, and the build quality of the iphone 5 isnt the best, my bumper and back started to loose there coating after 2 weeks the screen cracked from no more than a 30cm drop, I moved to android and I support open source all the way! Now my s4 I have owned nearly aslong as my 5 and yeah it has gained a few scratches on the back which I can replace! But appart from that iv had no issues with build quality the screen is superb very resilient!
They should release a dumbed down version of android for the apple boys