Me and my roomatre recently decided that needle wear is bullshit and its just a matter of cleaning your needles with a small brush and some rubbing alcohol. He has this pen microscope, pretty cool device, and we looked at both the needle i cut on and the needle i use to just play beats. after cleaning the needle i usually cut with i ooked at both under the microscope and the shape/point was EXACTLY the same. think about it, how the fuck is a peice of plastic going to wear down a chunk of diamond???? myth busters 4 lyfe holmes.
First up unless you're Usher your stylus probably isn't made out of diamond. Diamond styli means the needle contact point is cut to diamond shape. It's still just metal.
Plus have you never had a worn down needle - the type tha just skate across the record?? I know I have and I'd rather my needles didn't get in that state too quickly.
Also record wear is very real. I thought I couldn't afford Shures when I first started out. I wish I'd just bought them though as they'd have been a great investment. I ruined a whole load of nice vinyl scratching with Shures with 5ps on the carts (how was I supposed to know???)