>Tesla seems to be taking the opposite approach to Apple here. In my observation, Apple drives its suppliers extremely hard to achieve the quality it requires.

Apple earned this right by helping those suppliers get off the ground. With introduction of iMacs/iBooks (~1999) Apple helped build wireless card manufacturing plant in Taiwan from nothing ('few dusty rooms' at their modem supplier manufacturing facility). They did similar thing while shopping for Camera supplier, instead of going with someone established like Sony Apple chose Taiwanese bottom of the barrel volume suppliers (Primax/Micron) and grew their camera module divisions with each iteration of iPhone.