Most people don't choose lock-in. They choose a provider that works for them on the budget and timeline that they have, and they build on that. Expanding to multiple providers isn't always feasible depending on a company's business model and financial state - it takes time and development resources to do so, which can both be very sparse for company with tight profit margins.

You have to start somewhere. Unless you have been handed a substantial amount of starting money and baked "we need to be provider agnostic" into your company beliefs from the beginning, it's rarely an early priority. Becoming profitable is usually what comes first. Securing a stronger foundation for your platform comes over time.

> If you don't want to talk about fault, fine, but then don't go on to talk about fault :)

What is the point of saying this?