On the contrary, I think this just goes to show how challenging it is to build a business that is 100% defensible, and doesn't rely on another platform/company.

On the contrary, I think this just goes to show how challenging it is to build a business that is 100% defensible, and doesn't rely on another platform/company. Building an app? OK, better hope it doesn't violate Apple's TOS. Building a consumer website? OK, better hope Google's next update doesn't affect you negatively. Building a Buffer competitor? OK, better hope Twitter doesn't ban you from their API