The problem with any thicker metal punched out by a press ( and the steel backing of pads is pretty thick ) is that the edges are not parallel, so the sides if the 'ears' are tapered from front to back. I have found that a little bit removed when the pads are fitted will prevent any re-visiting at a later date to fix sticking calipers, which can either be caused by the slide pins getting tight ( easily avoidable if you check and re-lube the pins with something like TRW PFG110 ( rubber friendly brake grease, do not use petroleum based grease anywhere near rubber gaiters or seals as it makes them swell and disintegrate and make sure the rubber concertina gaiters are intact and fitted properly). Only need a smear of brake grease on the pins, be careful not to put too much on, if too much grease gets into the blind hole where the pins slide it can stop the pins sliding ( hydraulic lock, as the grease won't compress and cannot get back out past the pin very easily ).
The other thing that cause calipers to stick is if the ears are too tight in their slots, and especially on Jazz rear discs they get rusty and swell up ( rust takes up more room than the steel it forms on ) and bind, before I started cleaning up the ears I had this happen a couple of times despite fitting new shims and cleaning out the slots.
When the pads or pins stick the result is that the calipers do not equalise around the disc and that causes one pad to wear a lot more than the other, unfortunately that is normally the inside pad where the cylinder is mounted, so when you look at the pads the one you can see easily ( the outside one) normally has plenty of material left, the first warning you may get is when the squeal clip starts rubbing on the disc and makes an awful racket when you brake.