All these arguments were also said when Apple replaced Firewire/mini-DVI/... by Thunderbolt, a fantastic new standard, and we all had to buy the adapters that we'll now throw away.

It seems that USB-C will be more successful than Thunderbolt 1/2 have been, but Apple really isn't helping it with the way they're doing the switch (some devices USB-C only, some devices USB-A only, Lightning headphones...).