Ok, so who is responsible for devices that are "repaired" by third parties who in turn mess them up? At one point or another I have repaired every Phone up through the Phone 6. Usually because myself or my kids broke the screen. I have never had problems getting cheap parts from Amazon, nor any problem with screwdrivers or even replacement screws. BUT the repairs are NOT for the faint of heart, it is tricky, takes time and practice. I happen to have skills in this area so it doesn't bother me; but I wouldn't want to see someone just try and wing it, likely they'll break things worse.
The reality is, Apple's fee for most repairs is not that bad, typically about $100.