Authentication sucks, technology or business error?

I think there should be a law for all business to adapt a common authentication protocol. Why ? We have unlimited number of businesses, now as a customer, we want to have common way to integrate new services on top of existing services. But most of small business doesn't have a way to allow integrating authentication to adapt. IT SUCKS! So is this techonology or business decisor's error ? Let's stop this happen anymore. One typical example: OpenProject product. Their cloud service doesn't even have a way to integrate external authentication mechanism. So, how can i integrate it on top of our userbase ? Note: By Authentication, i mean it's combination of registration, login, password recovery.