Well, two things:
1) On iOS, Apple have a record of disabling third-party cables through software updates. Ask me how I know. :)
2) USB-C cables have a horrible reputation for quality control that's all over the place. This is one place where Apple might have a leg up, because a third-party cable could literally blow up your computer.
Honestly, it's mainly the combination of the high price tag and their shitty build quality that leads to near-instant fraying that pisses me off about Apple cables more than anything.